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      1 /*
      2  * Copyright (C) 2006 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.text.format;
     18 
     19 import com.android.internal.R;
     20 
     21 import android.content.Context;
     22 import android.content.res.Configuration;
     23 import android.content.res.Resources;
     24 
     25 import java.util.Calendar;
     26 import java.util.Date;
     27 import java.util.Formatter;
     28 import java.util.GregorianCalendar;
     29 import java.util.Locale;
     30 import java.util.TimeZone;
     31 
     32 /**
     33  * This class contains various date-related utilities for creating text for things like
     34  * elapsed time and date ranges, strings for days of the week and months, and AM/PM text etc.
     35  */
     36 public class DateUtils
     37 {
     38     private static final Object sLock = new Object();
     39     private static final int[] sDaysLong = new int[] {
     40             com.android.internal.R.string.day_of_week_long_sunday,
     41             com.android.internal.R.string.day_of_week_long_monday,
     42             com.android.internal.R.string.day_of_week_long_tuesday,
     43             com.android.internal.R.string.day_of_week_long_wednesday,
     44             com.android.internal.R.string.day_of_week_long_thursday,
     45             com.android.internal.R.string.day_of_week_long_friday,
     46             com.android.internal.R.string.day_of_week_long_saturday,
     47         };
     48     private static final int[] sDaysMedium = new int[] {
     49             com.android.internal.R.string.day_of_week_medium_sunday,
     50             com.android.internal.R.string.day_of_week_medium_monday,
     51             com.android.internal.R.string.day_of_week_medium_tuesday,
     52             com.android.internal.R.string.day_of_week_medium_wednesday,
     53             com.android.internal.R.string.day_of_week_medium_thursday,
     54             com.android.internal.R.string.day_of_week_medium_friday,
     55             com.android.internal.R.string.day_of_week_medium_saturday,
     56         };
     57     private static final int[] sDaysShort = new int[] {
     58             com.android.internal.R.string.day_of_week_short_sunday,
     59             com.android.internal.R.string.day_of_week_short_monday,
     60             com.android.internal.R.string.day_of_week_short_tuesday,
     61             com.android.internal.R.string.day_of_week_short_wednesday,
     62             com.android.internal.R.string.day_of_week_short_thursday,
     63             com.android.internal.R.string.day_of_week_short_friday,
     64             com.android.internal.R.string.day_of_week_short_saturday,
     65         };
     66     private static final int[] sDaysShortest = new int[] {
     67             com.android.internal.R.string.day_of_week_shortest_sunday,
     68             com.android.internal.R.string.day_of_week_shortest_monday,
     69             com.android.internal.R.string.day_of_week_shortest_tuesday,
     70             com.android.internal.R.string.day_of_week_shortest_wednesday,
     71             com.android.internal.R.string.day_of_week_shortest_thursday,
     72             com.android.internal.R.string.day_of_week_shortest_friday,
     73             com.android.internal.R.string.day_of_week_shortest_saturday,
     74         };
     75     private static final int[] sMonthsStandaloneLong = new int [] {
     76             com.android.internal.R.string.month_long_standalone_january,
     77             com.android.internal.R.string.month_long_standalone_february,
     78             com.android.internal.R.string.month_long_standalone_march,
     79             com.android.internal.R.string.month_long_standalone_april,
     80             com.android.internal.R.string.month_long_standalone_may,
     81             com.android.internal.R.string.month_long_standalone_june,
     82             com.android.internal.R.string.month_long_standalone_july,
     83             com.android.internal.R.string.month_long_standalone_august,
     84             com.android.internal.R.string.month_long_standalone_september,
     85             com.android.internal.R.string.month_long_standalone_october,
     86             com.android.internal.R.string.month_long_standalone_november,
     87             com.android.internal.R.string.month_long_standalone_december,
     88         };
     89     private static final int[] sMonthsLong = new int [] {
     90             com.android.internal.R.string.month_long_january,
     91             com.android.internal.R.string.month_long_february,
     92             com.android.internal.R.string.month_long_march,
     93             com.android.internal.R.string.month_long_april,
     94             com.android.internal.R.string.month_long_may,
     95             com.android.internal.R.string.month_long_june,
     96             com.android.internal.R.string.month_long_july,
     97             com.android.internal.R.string.month_long_august,
     98             com.android.internal.R.string.month_long_september,
     99             com.android.internal.R.string.month_long_october,
    100             com.android.internal.R.string.month_long_november,
    101             com.android.internal.R.string.month_long_december,
    102         };
    103     private static final int[] sMonthsMedium = new int [] {
    104             com.android.internal.R.string.month_medium_january,
    105             com.android.internal.R.string.month_medium_february,
    106             com.android.internal.R.string.month_medium_march,
    107             com.android.internal.R.string.month_medium_april,
    108             com.android.internal.R.string.month_medium_may,
    109             com.android.internal.R.string.month_medium_june,
    110             com.android.internal.R.string.month_medium_july,
    111             com.android.internal.R.string.month_medium_august,
    112             com.android.internal.R.string.month_medium_september,
    113             com.android.internal.R.string.month_medium_october,
    114             com.android.internal.R.string.month_medium_november,
    115             com.android.internal.R.string.month_medium_december,
    116         };
    117     private static final int[] sMonthsShortest = new int [] {
    118             com.android.internal.R.string.month_shortest_january,
    119             com.android.internal.R.string.month_shortest_february,
    120             com.android.internal.R.string.month_shortest_march,
    121             com.android.internal.R.string.month_shortest_april,
    122             com.android.internal.R.string.month_shortest_may,
    123             com.android.internal.R.string.month_shortest_june,
    124             com.android.internal.R.string.month_shortest_july,
    125             com.android.internal.R.string.month_shortest_august,
    126             com.android.internal.R.string.month_shortest_september,
    127             com.android.internal.R.string.month_shortest_october,
    128             com.android.internal.R.string.month_shortest_november,
    129             com.android.internal.R.string.month_shortest_december,
    130         };
    131     private static final int[] sAmPm = new int[] {
    132             com.android.internal.R.string.am,
    133             com.android.internal.R.string.pm,
    134         };
    135     private static Configuration sLastConfig;
    136     private static java.text.DateFormat sStatusTimeFormat;
    137     private static String sElapsedFormatMMSS;
    138     private static String sElapsedFormatHMMSS;
    139 
    140     private static final String FAST_FORMAT_HMMSS = "%1$d:%2$02d:%3$02d";
    141     private static final String FAST_FORMAT_MMSS = "%1$02d:%2$02d";
    142     private static final char TIME_PADDING = '0';
    143     private static final char TIME_SEPARATOR = ':';
    144 
    145 
    146     public static final long SECOND_IN_MILLIS = 1000;
    147     public static final long MINUTE_IN_MILLIS = SECOND_IN_MILLIS * 60;
    148     public static final long HOUR_IN_MILLIS = MINUTE_IN_MILLIS * 60;
    149     public static final long DAY_IN_MILLIS = HOUR_IN_MILLIS * 24;
    150     public static final long WEEK_IN_MILLIS = DAY_IN_MILLIS * 7;
    151     /**
    152      * This constant is actually the length of 364 days, not of a year!
    153      */
    154     public static final long YEAR_IN_MILLIS = WEEK_IN_MILLIS * 52;
    155 
    156     // The following FORMAT_* symbols are used for specifying the format of
    157     // dates and times in the formatDateRange method.
    158     public static final int FORMAT_SHOW_TIME = 0x00001;
    159     public static final int FORMAT_SHOW_WEEKDAY = 0x00002;
    160     public static final int FORMAT_SHOW_YEAR = 0x00004;
    161     public static final int FORMAT_NO_YEAR = 0x00008;
    162     public static final int FORMAT_SHOW_DATE = 0x00010;
    163     public static final int FORMAT_NO_MONTH_DAY = 0x00020;
    164     public static final int FORMAT_12HOUR = 0x00040;
    165     public static final int FORMAT_24HOUR = 0x00080;
    166     public static final int FORMAT_CAP_AMPM = 0x00100;
    167     public static final int FORMAT_NO_NOON = 0x00200;
    168     public static final int FORMAT_CAP_NOON = 0x00400;
    169     public static final int FORMAT_NO_MIDNIGHT = 0x00800;
    170     public static final int FORMAT_CAP_MIDNIGHT = 0x01000;
    171     /**
    172      * @deprecated Use
    173      * {@link #formatDateRange(Context, Formatter, long, long, int, String) formatDateRange}
    174      * and pass in {@link Time#TIMEZONE_UTC Time.TIMEZONE_UTC} for the timeZone instead.
    175      */
    176     @Deprecated
    177     public static final int FORMAT_UTC = 0x02000;
    178     public static final int FORMAT_ABBREV_TIME = 0x04000;
    179     public static final int FORMAT_ABBREV_WEEKDAY = 0x08000;
    180     public static final int FORMAT_ABBREV_MONTH = 0x10000;
    181     public static final int FORMAT_NUMERIC_DATE = 0x20000;
    182     public static final int FORMAT_ABBREV_RELATIVE = 0x40000;
    183     public static final int FORMAT_ABBREV_ALL = 0x80000;
    184     public static final int FORMAT_CAP_NOON_MIDNIGHT = (FORMAT_CAP_NOON | FORMAT_CAP_MIDNIGHT);
    185     public static final int FORMAT_NO_NOON_MIDNIGHT = (FORMAT_NO_NOON | FORMAT_NO_MIDNIGHT);
    186 
    187     // Date and time format strings that are constant and don't need to be
    188     // translated.
    189     /**
    190      * This is not actually the preferred 24-hour date format in all locales.
    191      */
    192     public static final String HOUR_MINUTE_24 = "%H:%M";
    193     public static final String MONTH_FORMAT = "%B";
    194     /**
    195      * This is not actually a useful month name in all locales.
    196      */
    197     public static final String ABBREV_MONTH_FORMAT = "%b";
    198     public static final String NUMERIC_MONTH_FORMAT = "%m";
    199     public static final String MONTH_DAY_FORMAT = "%-d";
    200     public static final String YEAR_FORMAT = "%Y";
    201     public static final String YEAR_FORMAT_TWO_DIGITS = "%g";
    202     public static final String WEEKDAY_FORMAT = "%A";
    203     public static final String ABBREV_WEEKDAY_FORMAT = "%a";
    204 
    205     // This table is used to lookup the resource string id of a format string
    206     // used for formatting a start and end date that fall in the same year.
    207     // The index is constructed from a bit-wise OR of the boolean values:
    208     // {showTime, showYear, showWeekDay}.  For example, if showYear and
    209     // showWeekDay are both true, then the index would be 3.
    210     public static final int sameYearTable[] = {
    211         com.android.internal.R.string.same_year_md1_md2,
    212         com.android.internal.R.string.same_year_wday1_md1_wday2_md2,
    213         com.android.internal.R.string.same_year_mdy1_mdy2,
    214         com.android.internal.R.string.same_year_wday1_mdy1_wday2_mdy2,
    215         com.android.internal.R.string.same_year_md1_time1_md2_time2,
    216         com.android.internal.R.string.same_year_wday1_md1_time1_wday2_md2_time2,
    217         com.android.internal.R.string.same_year_mdy1_time1_mdy2_time2,
    218         com.android.internal.R.string.same_year_wday1_mdy1_time1_wday2_mdy2_time2,
    219 
    220         // Numeric date strings
    221         com.android.internal.R.string.numeric_md1_md2,
    222         com.android.internal.R.string.numeric_wday1_md1_wday2_md2,
    223         com.android.internal.R.string.numeric_mdy1_mdy2,
    224         com.android.internal.R.string.numeric_wday1_mdy1_wday2_mdy2,
    225         com.android.internal.R.string.numeric_md1_time1_md2_time2,
    226         com.android.internal.R.string.numeric_wday1_md1_time1_wday2_md2_time2,
    227         com.android.internal.R.string.numeric_mdy1_time1_mdy2_time2,
    228         com.android.internal.R.string.numeric_wday1_mdy1_time1_wday2_mdy2_time2,
    229     };
    230 
    231     // This table is used to lookup the resource string id of a format string
    232     // used for formatting a start and end date that fall in the same month.
    233     // The index is constructed from a bit-wise OR of the boolean values:
    234     // {showTime, showYear, showWeekDay}.  For example, if showYear and
    235     // showWeekDay are both true, then the index would be 3.
    236     public static final int sameMonthTable[] = {
    237         com.android.internal.R.string.same_month_md1_md2,
    238         com.android.internal.R.string.same_month_wday1_md1_wday2_md2,
    239         com.android.internal.R.string.same_month_mdy1_mdy2,
    240         com.android.internal.R.string.same_month_wday1_mdy1_wday2_mdy2,
    241         com.android.internal.R.string.same_month_md1_time1_md2_time2,
    242         com.android.internal.R.string.same_month_wday1_md1_time1_wday2_md2_time2,
    243         com.android.internal.R.string.same_month_mdy1_time1_mdy2_time2,
    244         com.android.internal.R.string.same_month_wday1_mdy1_time1_wday2_mdy2_time2,
    245 
    246         com.android.internal.R.string.numeric_md1_md2,
    247         com.android.internal.R.string.numeric_wday1_md1_wday2_md2,
    248         com.android.internal.R.string.numeric_mdy1_mdy2,
    249         com.android.internal.R.string.numeric_wday1_mdy1_wday2_mdy2,
    250         com.android.internal.R.string.numeric_md1_time1_md2_time2,
    251         com.android.internal.R.string.numeric_wday1_md1_time1_wday2_md2_time2,
    252         com.android.internal.R.string.numeric_mdy1_time1_mdy2_time2,
    253         com.android.internal.R.string.numeric_wday1_mdy1_time1_wday2_mdy2_time2,
    254     };
    255 
    256     /**
    257      * Request the full spelled-out name. For use with the 'abbrev' parameter of
    258      * {@link #getDayOfWeekString} and {@link #getMonthString}.
    259      *
    260      * @more <p>
    261      *       e.g. "Sunday" or "January"
    262      */
    263     public static final int LENGTH_LONG = 10;
    264 
    265     /**
    266      * Request an abbreviated version of the name. For use with the 'abbrev'
    267      * parameter of {@link #getDayOfWeekString} and {@link #getMonthString}.
    268      *
    269      * @more <p>
    270      *       e.g. "Sun" or "Jan"
    271      */
    272     public static final int LENGTH_MEDIUM = 20;
    273 
    274     /**
    275      * Request a shorter abbreviated version of the name.
    276      * For use with the 'abbrev' parameter of {@link #getDayOfWeekString} and {@link #getMonthString}.
    277      * @more
    278      * <p>e.g. "Su" or "Jan"
    279      * <p>In most languages, the results returned for LENGTH_SHORT will be the same as
    280      * the results returned for {@link #LENGTH_MEDIUM}.
    281      */
    282     public static final int LENGTH_SHORT = 30;
    283 
    284     /**
    285      * Request an even shorter abbreviated version of the name.
    286      * Do not use this.  Currently this will always return the same result
    287      * as {@link #LENGTH_SHORT}.
    288      */
    289     public static final int LENGTH_SHORTER = 40;
    290 
    291     /**
    292      * Request an even shorter abbreviated version of the name.
    293      * For use with the 'abbrev' parameter of {@link #getDayOfWeekString} and {@link #getMonthString}.
    294      * @more
    295      * <p>e.g. "S", "T", "T" or "J"
    296      * <p>In some languages, the results returned for LENGTH_SHORTEST will be the same as
    297      * the results returned for {@link #LENGTH_SHORT}.
    298      */
    299     public static final int LENGTH_SHORTEST = 50;
    300 
    301     /**
    302      * Return a string for the day of the week.
    303      * @param dayOfWeek One of {@link Calendar#SUNDAY Calendar.SUNDAY},
    304      *               {@link Calendar#MONDAY Calendar.MONDAY}, etc.
    305      * @param abbrev One of {@link #LENGTH_LONG}, {@link #LENGTH_SHORT},
    306      *               {@link #LENGTH_MEDIUM}, or {@link #LENGTH_SHORTEST}.
    307      *               Note that in most languages, {@link #LENGTH_SHORT}
    308      *               will return the same as {@link #LENGTH_MEDIUM}.
    309      *               Undefined lengths will return {@link #LENGTH_MEDIUM}
    310      *               but may return something different in the future.
    311      * @throws IndexOutOfBoundsException if the dayOfWeek is out of bounds.
    312      */
    313     public static String getDayOfWeekString(int dayOfWeek, int abbrev) {
    314         int[] list;
    315         switch (abbrev) {
    316             case LENGTH_LONG:       list = sDaysLong;       break;
    317             case LENGTH_MEDIUM:     list = sDaysMedium;     break;
    318             case LENGTH_SHORT:      list = sDaysShort;      break;
    319             case LENGTH_SHORTER:    list = sDaysShort;      break;
    320             case LENGTH_SHORTEST:   list = sDaysShortest;   break;
    321             default:                list = sDaysMedium;     break;
    322         }
    323 
    324         Resources r = Resources.getSystem();
    325         return r.getString(list[dayOfWeek - Calendar.SUNDAY]);
    326     }
    327 
    328     /**
    329      * Return a localized string for AM or PM.
    330      * @param ampm Either {@link Calendar#AM Calendar.AM} or {@link Calendar#PM Calendar.PM}.
    331      * @throws IndexOutOfBoundsException if the ampm is out of bounds.
    332      * @return Localized version of "AM" or "PM".
    333      */
    334     public static String getAMPMString(int ampm) {
    335         Resources r = Resources.getSystem();
    336         return r.getString(sAmPm[ampm - Calendar.AM]);
    337     }
    338 
    339     /**
    340      * Return a localized string for the month of the year.
    341      * @param month One of {@link Calendar#JANUARY Calendar.JANUARY},
    342      *               {@link Calendar#FEBRUARY Calendar.FEBRUARY}, etc.
    343      * @param abbrev One of {@link #LENGTH_LONG}, {@link #LENGTH_MEDIUM},
    344      *               or {@link #LENGTH_SHORTEST}.
    345      *               Undefined lengths will return {@link #LENGTH_MEDIUM}
    346      *               but may return something different in the future.
    347      * @return Localized month of the year.
    348      */
    349     public static String getMonthString(int month, int abbrev) {
    350         // Note that here we use sMonthsMedium for MEDIUM, SHORT and SHORTER.
    351         // This is a shortcut to not spam the translators with too many variations
    352         // of the same string.  If we find that in a language the distinction
    353         // is necessary, we can can add more without changing this API.
    354         int[] list;
    355         switch (abbrev) {
    356             case LENGTH_LONG:       list = sMonthsLong;     break;
    357             case LENGTH_MEDIUM:     list = sMonthsMedium;   break;
    358             case LENGTH_SHORT:      list = sMonthsMedium;   break;
    359             case LENGTH_SHORTER:    list = sMonthsMedium;   break;
    360             case LENGTH_SHORTEST:   list = sMonthsShortest; break;
    361             default:                list = sMonthsMedium;   break;
    362         }
    363 
    364         Resources r = Resources.getSystem();
    365         return r.getString(list[month - Calendar.JANUARY]);
    366     }
    367 
    368     /**
    369      * Return a localized string for the month of the year, for
    370      * contexts where the month is not formatted together with
    371      * a day of the month.
    372      *
    373      * @param month One of {@link Calendar#JANUARY Calendar.JANUARY},
    374      *               {@link Calendar#FEBRUARY Calendar.FEBRUARY}, etc.
    375      * @param abbrev One of {@link #LENGTH_LONG}, {@link #LENGTH_MEDIUM},
    376      *               or {@link #LENGTH_SHORTEST}.
    377      *               Undefined lengths will return {@link #LENGTH_MEDIUM}
    378      *               but may return something different in the future.
    379      * @return Localized month of the year.
    380      * @hide Pending API council approval
    381      */
    382     public static String getStandaloneMonthString(int month, int abbrev) {
    383         // Note that here we use sMonthsMedium for MEDIUM, SHORT and SHORTER.
    384         // This is a shortcut to not spam the translators with too many variations
    385         // of the same string.  If we find that in a language the distinction
    386         // is necessary, we can can add more without changing this API.
    387         int[] list;
    388         switch (abbrev) {
    389             case LENGTH_LONG:       list = sMonthsStandaloneLong;
    390                                                             break;
    391             case LENGTH_MEDIUM:     list = sMonthsMedium;   break;
    392             case LENGTH_SHORT:      list = sMonthsMedium;   break;
    393             case LENGTH_SHORTER:    list = sMonthsMedium;   break;
    394             case LENGTH_SHORTEST:   list = sMonthsShortest; break;
    395             default:                list = sMonthsMedium;   break;
    396         }
    397 
    398         Resources r = Resources.getSystem();
    399         return r.getString(list[month - Calendar.JANUARY]);
    400     }
    401 
    402     /**
    403      * Returns a string describing the elapsed time since startTime.
    404      * @param startTime some time in the past.
    405      * @return a String object containing the elapsed time.
    406      * @see #getRelativeTimeSpanString(long, long, long)
    407      */
    408     public static CharSequence getRelativeTimeSpanString(long startTime) {
    409         return getRelativeTimeSpanString(startTime, System.currentTimeMillis(), MINUTE_IN_MILLIS);
    410     }
    411 
    412     /**
    413      * Returns a string describing 'time' as a time relative to 'now'.
    414      * <p>
    415      * Time spans in the past are formatted like "42 minutes ago".
    416      * Time spans in the future are formatted like "in 42 minutes".
    417      *
    418      * @param time the time to describe, in milliseconds
    419      * @param now the current time in milliseconds
    420      * @param minResolution the minimum timespan to report. For example, a time 3 seconds in the
    421      *     past will be reported as "0 minutes ago" if this is set to MINUTE_IN_MILLIS. Pass one of
    422      *     0, MINUTE_IN_MILLIS, HOUR_IN_MILLIS, DAY_IN_MILLIS, WEEK_IN_MILLIS
    423      */
    424     public static CharSequence getRelativeTimeSpanString(long time, long now, long minResolution) {
    425         int flags = FORMAT_SHOW_DATE | FORMAT_SHOW_YEAR | FORMAT_ABBREV_MONTH;
    426         return getRelativeTimeSpanString(time, now, minResolution, flags);
    427     }
    428 
    429     /**
    430      * Returns a string describing 'time' as a time relative to 'now'.
    431      * <p>
    432      * Time spans in the past are formatted like "42 minutes ago". Time spans in
    433      * the future are formatted like "in 42 minutes".
    434      * <p>
    435      * Can use {@link #FORMAT_ABBREV_RELATIVE} flag to use abbreviated relative
    436      * times, like "42 mins ago".
    437      *
    438      * @param time the time to describe, in milliseconds
    439      * @param now the current time in milliseconds
    440      * @param minResolution the minimum timespan to report. For example, a time
    441      *            3 seconds in the past will be reported as "0 minutes ago" if
    442      *            this is set to MINUTE_IN_MILLIS. Pass one of 0,
    443      *            MINUTE_IN_MILLIS, HOUR_IN_MILLIS, DAY_IN_MILLIS,
    444      *            WEEK_IN_MILLIS
    445      * @param flags a bit mask of formatting options, such as
    446      *            {@link #FORMAT_NUMERIC_DATE} or
    447      *            {@link #FORMAT_ABBREV_RELATIVE}
    448      */
    449     public static CharSequence getRelativeTimeSpanString(long time, long now, long minResolution,
    450             int flags) {
    451         Resources r = Resources.getSystem();
    452         boolean abbrevRelative = (flags & (FORMAT_ABBREV_RELATIVE | FORMAT_ABBREV_ALL)) != 0;
    453 
    454         boolean past = (now >= time);
    455         long duration = Math.abs(now - time);
    456 
    457         int resId;
    458         long count;
    459         if (duration < MINUTE_IN_MILLIS && minResolution < MINUTE_IN_MILLIS) {
    460             count = duration / SECOND_IN_MILLIS;
    461             if (past) {
    462                 if (abbrevRelative) {
    463                     resId = com.android.internal.R.plurals.abbrev_num_seconds_ago;
    464                 } else {
    465                     resId = com.android.internal.R.plurals.num_seconds_ago;
    466                 }
    467             } else {
    468                 if (abbrevRelative) {
    469                     resId = com.android.internal.R.plurals.abbrev_in_num_seconds;
    470                 } else {
    471                     resId = com.android.internal.R.plurals.in_num_seconds;
    472                 }
    473             }
    474         } else if (duration < HOUR_IN_MILLIS && minResolution < HOUR_IN_MILLIS) {
    475             count = duration / MINUTE_IN_MILLIS;
    476             if (past) {
    477                 if (abbrevRelative) {
    478                     resId = com.android.internal.R.plurals.abbrev_num_minutes_ago;
    479                 } else {
    480                     resId = com.android.internal.R.plurals.num_minutes_ago;
    481                 }
    482             } else {
    483                 if (abbrevRelative) {
    484                     resId = com.android.internal.R.plurals.abbrev_in_num_minutes;
    485                 } else {
    486                     resId = com.android.internal.R.plurals.in_num_minutes;
    487                 }
    488             }
    489         } else if (duration < DAY_IN_MILLIS && minResolution < DAY_IN_MILLIS) {
    490             count = duration / HOUR_IN_MILLIS;
    491             if (past) {
    492                 if (abbrevRelative) {
    493                     resId = com.android.internal.R.plurals.abbrev_num_hours_ago;
    494                 } else {
    495                     resId = com.android.internal.R.plurals.num_hours_ago;
    496                 }
    497             } else {
    498                 if (abbrevRelative) {
    499                     resId = com.android.internal.R.plurals.abbrev_in_num_hours;
    500                 } else {
    501                     resId = com.android.internal.R.plurals.in_num_hours;
    502                 }
    503             }
    504         } else if (duration < WEEK_IN_MILLIS && minResolution < WEEK_IN_MILLIS) {
    505             count = getNumberOfDaysPassed(time, now);
    506             if (past) {
    507                 if (abbrevRelative) {
    508                     resId = com.android.internal.R.plurals.abbrev_num_days_ago;
    509                 } else {
    510                     resId = com.android.internal.R.plurals.num_days_ago;
    511                 }
    512             } else {
    513                 if (abbrevRelative) {
    514                     resId = com.android.internal.R.plurals.abbrev_in_num_days;
    515                 } else {
    516                     resId = com.android.internal.R.plurals.in_num_days;
    517                 }
    518             }
    519         } else {
    520             // We know that we won't be showing the time, so it is safe to pass
    521             // in a null context.
    522             return formatDateRange(null, time, time, flags);
    523         }
    524 
    525         String format = r.getQuantityString(resId, (int) count);
    526         return String.format(format, count);
    527     }
    528 
    529     /**
    530      * Returns the number of days passed between two dates.
    531      *
    532      * @param date1 first date
    533      * @param date2 second date
    534      * @return number of days passed between to dates.
    535      */
    536     private synchronized static long getNumberOfDaysPassed(long date1, long date2) {
    537         if (sThenTime == null) {
    538             sThenTime = new Time();
    539         }
    540         sThenTime.set(date1);
    541         int day1 = Time.getJulianDay(date1, sThenTime.gmtoff);
    542         sThenTime.set(date2);
    543         int day2 = Time.getJulianDay(date2, sThenTime.gmtoff);
    544         return Math.abs(day2 - day1);
    545     }
    546 
    547     /**
    548      * Return string describing the elapsed time since startTime formatted like
    549      * "[relative time/date], [time]".
    550      * <p>
    551      * Example output strings for the US date format.
    552      * <ul>
    553      * <li>3 mins ago, 10:15 AM</li>
    554      * <li>yesterday, 12:20 PM</li>
    555      * <li>Dec 12, 4:12 AM</li>
    556      * <li>11/14/2007, 8:20 AM</li>
    557      * </ul>
    558      *
    559      * @param time some time in the past.
    560      * @param minResolution the minimum elapsed time (in milliseconds) to report
    561      *            when showing relative times. For example, a time 3 seconds in
    562      *            the past will be reported as "0 minutes ago" if this is set to
    563      *            {@link #MINUTE_IN_MILLIS}.
    564      * @param transitionResolution the elapsed time (in milliseconds) at which
    565      *            to stop reporting relative measurements. Elapsed times greater
    566      *            than this resolution will default to normal date formatting.
    567      *            For example, will transition from "6 days ago" to "Dec 12"
    568      *            when using {@link #WEEK_IN_MILLIS}.
    569      */
    570     public static CharSequence getRelativeDateTimeString(Context c, long time, long minResolution,
    571             long transitionResolution, int flags) {
    572         Resources r = Resources.getSystem();
    573 
    574         long now = System.currentTimeMillis();
    575         long duration = Math.abs(now - time);
    576 
    577         // getRelativeTimeSpanString() doesn't correctly format relative dates
    578         // above a week or exact dates below a day, so clamp
    579         // transitionResolution as needed.
    580         if (transitionResolution > WEEK_IN_MILLIS) {
    581             transitionResolution = WEEK_IN_MILLIS;
    582         } else if (transitionResolution < DAY_IN_MILLIS) {
    583             transitionResolution = DAY_IN_MILLIS;
    584         }
    585 
    586         CharSequence timeClause = formatDateRange(c, time, time, FORMAT_SHOW_TIME);
    587 
    588         String result;
    589         if (duration < transitionResolution) {
    590             CharSequence relativeClause = getRelativeTimeSpanString(time, now, minResolution, flags);
    591             result = r.getString(com.android.internal.R.string.relative_time, relativeClause, timeClause);
    592         } else {
    593             CharSequence dateClause = getRelativeTimeSpanString(c, time, false);
    594             result = r.getString(com.android.internal.R.string.date_time, dateClause, timeClause);
    595         }
    596 
    597         return result;
    598     }
    599 
    600     /**
    601      * Returns a string describing a day relative to the current day. For example if the day is
    602      * today this function returns "Today", if the day was a week ago it returns "7 days ago", and
    603      * if the day is in 2 weeks it returns "in 14 days".
    604      *
    605      * @param r the resources to get the strings from
    606      * @param day the relative day to describe in UTC milliseconds
    607      * @param today the current time in UTC milliseconds
    608      * @return a formatting string
    609      */
    610     private static final String getRelativeDayString(Resources r, long day, long today) {
    611         Time startTime = new Time();
    612         startTime.set(day);
    613         Time currentTime = new Time();
    614         currentTime.set(today);
    615 
    616         int startDay = Time.getJulianDay(day, startTime.gmtoff);
    617         int currentDay = Time.getJulianDay(today, currentTime.gmtoff);
    618 
    619         int days = Math.abs(currentDay - startDay);
    620         boolean past = (today > day);
    621 
    622         if (days == 1) {
    623             if (past) {
    624                 return r.getString(com.android.internal.R.string.yesterday);
    625             } else {
    626                 return r.getString(com.android.internal.R.string.tomorrow);
    627             }
    628         } else if (days == 0) {
    629             return r.getString(com.android.internal.R.string.today);
    630         }
    631 
    632         int resId;
    633         if (past) {
    634             resId = com.android.internal.R.plurals.num_days_ago;
    635         } else {
    636             resId = com.android.internal.R.plurals.in_num_days;
    637         }
    638 
    639         String format = r.getQuantityString(resId, days);
    640         return String.format(format, days);
    641     }
    642 
    643     private static void initFormatStrings() {
    644         synchronized (sLock) {
    645             initFormatStringsLocked();
    646         }
    647     }
    648 
    649     private static void initFormatStringsLocked() {
    650         Resources r = Resources.getSystem();
    651         Configuration cfg = r.getConfiguration();
    652         if (sLastConfig == null || !sLastConfig.equals(cfg)) {
    653             sLastConfig = cfg;
    654             sStatusTimeFormat = java.text.DateFormat.getTimeInstance(java.text.DateFormat.SHORT);
    655             sElapsedFormatMMSS = r.getString(com.android.internal.R.string.elapsed_time_short_format_mm_ss);
    656             sElapsedFormatHMMSS = r.getString(com.android.internal.R.string.elapsed_time_short_format_h_mm_ss);
    657         }
    658     }
    659 
    660     /**
    661      * Format a time so it appears like it would in the status bar clock.
    662      * @deprecated use {@link #DateFormat.getTimeFormat(Context)} instead.
    663      * @hide
    664      */
    665     public static final CharSequence timeString(long millis) {
    666         synchronized (sLock) {
    667             initFormatStringsLocked();
    668             return sStatusTimeFormat.format(millis);
    669         }
    670     }
    671 
    672     /**
    673      * Formats an elapsed time in the form "MM:SS" or "H:MM:SS"
    674      * for display on the call-in-progress screen.
    675      * @param elapsedSeconds the elapsed time in seconds.
    676      */
    677     public static String formatElapsedTime(long elapsedSeconds) {
    678         return formatElapsedTime(null, elapsedSeconds);
    679     }
    680 
    681     /**
    682      * Formats an elapsed time in the form "MM:SS" or "H:MM:SS"
    683      * for display on the call-in-progress screen.
    684      *
    685      * @param recycle {@link StringBuilder} to recycle, if possible
    686      * @param elapsedSeconds the elapsed time in seconds.
    687      */
    688     public static String formatElapsedTime(StringBuilder recycle, long elapsedSeconds) {
    689         initFormatStrings();
    690 
    691         long hours = 0;
    692         long minutes = 0;
    693         long seconds = 0;
    694 
    695         if (elapsedSeconds >= 3600) {
    696             hours = elapsedSeconds / 3600;
    697             elapsedSeconds -= hours * 3600;
    698         }
    699         if (elapsedSeconds >= 60) {
    700             minutes = elapsedSeconds / 60;
    701             elapsedSeconds -= minutes * 60;
    702         }
    703         seconds = elapsedSeconds;
    704 
    705         String result;
    706         if (hours > 0) {
    707             return formatElapsedTime(recycle, sElapsedFormatHMMSS, hours, minutes, seconds);
    708         } else {
    709             return formatElapsedTime(recycle, sElapsedFormatMMSS, minutes, seconds);
    710         }
    711     }
    712 
    713     /**
    714      * Fast formatting of h:mm:ss
    715      */
    716     private static String formatElapsedTime(StringBuilder recycle, String format, long hours,
    717             long minutes, long seconds) {
    718         if (FAST_FORMAT_HMMSS.equals(format)) {
    719             StringBuilder sb = recycle;
    720             if (sb == null) {
    721                 sb = new StringBuilder(8);
    722             } else {
    723                 sb.setLength(0);
    724             }
    725             sb.append(hours);
    726             sb.append(TIME_SEPARATOR);
    727             if (minutes < 10) {
    728                 sb.append(TIME_PADDING);
    729             } else {
    730                 sb.append(toDigitChar(minutes / 10));
    731             }
    732             sb.append(toDigitChar(minutes % 10));
    733             sb.append(TIME_SEPARATOR);
    734             if (seconds < 10) {
    735                 sb.append(TIME_PADDING);
    736             } else {
    737                 sb.append(toDigitChar(seconds / 10));
    738             }
    739             sb.append(toDigitChar(seconds % 10));
    740             return sb.toString();
    741         } else {
    742             return String.format(format, hours, minutes, seconds);
    743         }
    744     }
    745 
    746     /**
    747      * Fast formatting of m:ss
    748      */
    749     private static String formatElapsedTime(StringBuilder recycle, String format, long minutes,
    750             long seconds) {
    751         if (FAST_FORMAT_MMSS.equals(format)) {
    752             StringBuilder sb = recycle;
    753             if (sb == null) {
    754                 sb = new StringBuilder(8);
    755             } else {
    756                 sb.setLength(0);
    757             }
    758             if (minutes < 10) {
    759                 sb.append(TIME_PADDING);
    760             } else {
    761                 sb.append(toDigitChar(minutes / 10));
    762             }
    763             sb.append(toDigitChar(minutes % 10));
    764             sb.append(TIME_SEPARATOR);
    765             if (seconds < 10) {
    766                 sb.append(TIME_PADDING);
    767             } else {
    768                 sb.append(toDigitChar(seconds / 10));
    769             }
    770             sb.append(toDigitChar(seconds % 10));
    771             return sb.toString();
    772         } else {
    773             return String.format(format, minutes, seconds);
    774         }
    775     }
    776 
    777     private static char toDigitChar(long digit) {
    778         return (char) (digit + '0');
    779     }
    780 
    781     /**
    782      * Format a date / time such that if the then is on the same day as now, it shows
    783      * just the time and if it's a different day, it shows just the date.
    784      *
    785      * <p>The parameters dateFormat and timeFormat should each be one of
    786      * {@link java.text.DateFormat#DEFAULT},
    787      * {@link java.text.DateFormat#FULL},
    788      * {@link java.text.DateFormat#LONG},
    789      * {@link java.text.DateFormat#MEDIUM}
    790      * or
    791      * {@link java.text.DateFormat#SHORT}
    792      *
    793      * @param then the date to format
    794      * @param now the base time
    795      * @param dateStyle how to format the date portion.
    796      * @param timeStyle how to format the time portion.
    797      */
    798     public static final CharSequence formatSameDayTime(long then, long now,
    799             int dateStyle, int timeStyle) {
    800         Calendar thenCal = new GregorianCalendar();
    801         thenCal.setTimeInMillis(then);
    802         Date thenDate = thenCal.getTime();
    803         Calendar nowCal = new GregorianCalendar();
    804         nowCal.setTimeInMillis(now);
    805 
    806         java.text.DateFormat f;
    807 
    808         if (thenCal.get(Calendar.YEAR) == nowCal.get(Calendar.YEAR)
    809                 && thenCal.get(Calendar.MONTH) == nowCal.get(Calendar.MONTH)
    810                 && thenCal.get(Calendar.DAY_OF_MONTH) == nowCal.get(Calendar.DAY_OF_MONTH)) {
    811             f = java.text.DateFormat.getTimeInstance(timeStyle);
    812         } else {
    813             f = java.text.DateFormat.getDateInstance(dateStyle);
    814         }
    815         return f.format(thenDate);
    816     }
    817 
    818     /**
    819      * @hide
    820      * @deprecated use {@link android.text.format.Time}
    821      */
    822     public static Calendar newCalendar(boolean zulu)
    823     {
    824         if (zulu)
    825             return Calendar.getInstance(TimeZone.getTimeZone("GMT"));
    826 
    827         return Calendar.getInstance();
    828     }
    829 
    830     /**
    831      * @return true if the supplied when is today else false
    832      */
    833     public static boolean isToday(long when) {
    834         Time time = new Time();
    835         time.set(when);
    836 
    837         int thenYear = time.year;
    838         int thenMonth = time.month;
    839         int thenMonthDay = time.monthDay;
    840 
    841         time.set(System.currentTimeMillis());
    842         return (thenYear == time.year)
    843                 && (thenMonth == time.month)
    844                 && (thenMonthDay == time.monthDay);
    845     }
    846 
    847     /**
    848      * @hide
    849      * @deprecated use {@link android.text.format.Time}
    850      * Return true if this date string is local time
    851      */
    852     public static boolean isUTC(String s)
    853     {
    854         if (s.length() == 16 && s.charAt(15) == 'Z') {
    855             return true;
    856         }
    857         if (s.length() == 9 && s.charAt(8) == 'Z') {
    858             // XXX not sure if this case possible/valid
    859             return true;
    860         }
    861         return false;
    862     }
    863 
    864     /**
    865      * Return a string containing the date and time in RFC2445 format.
    866      * Ensures that the time is written in UTC.  The Calendar class doesn't
    867      * really help out with this, so this is slower than it ought to be.
    868      *
    869      * @param cal the date and time to write
    870      * @hide
    871      * @deprecated use {@link android.text.format.Time}
    872      */
    873     public static String writeDateTime(Calendar cal)
    874     {
    875         TimeZone tz = TimeZone.getTimeZone("GMT");
    876         GregorianCalendar c = new GregorianCalendar(tz);
    877         c.setTimeInMillis(cal.getTimeInMillis());
    878         return writeDateTime(c, true);
    879     }
    880 
    881     /**
    882      * Return a string containing the date and time in RFC2445 format.
    883      *
    884      * @param cal the date and time to write
    885      * @param zulu If the calendar is in UTC, pass true, and a Z will
    886      * be written at the end as per RFC2445.  Otherwise, the time is
    887      * considered in localtime.
    888      * @hide
    889      * @deprecated use {@link android.text.format.Time}
    890      */
    891     public static String writeDateTime(Calendar cal, boolean zulu)
    892     {
    893         StringBuilder sb = new StringBuilder();
    894         sb.ensureCapacity(16);
    895         if (zulu) {
    896             sb.setLength(16);
    897             sb.setCharAt(15, 'Z');
    898         } else {
    899             sb.setLength(15);
    900         }
    901         return writeDateTime(cal, sb);
    902     }
    903 
    904     /**
    905      * Return a string containing the date and time in RFC2445 format.
    906      *
    907      * @param cal the date and time to write
    908      * @param sb a StringBuilder to use.  It is assumed that setLength
    909      *           has already been called on sb to the appropriate length
    910      *           which is sb.setLength(zulu ? 16 : 15)
    911      * @hide
    912      * @deprecated use {@link android.text.format.Time}
    913      */
    914     public static String writeDateTime(Calendar cal, StringBuilder sb)
    915     {
    916         int n;
    917 
    918         n = cal.get(Calendar.YEAR);
    919         sb.setCharAt(3, (char)('0'+n%10));
    920         n /= 10;
    921         sb.setCharAt(2, (char)('0'+n%10));
    922         n /= 10;
    923         sb.setCharAt(1, (char)('0'+n%10));
    924         n /= 10;
    925         sb.setCharAt(0, (char)('0'+n%10));
    926 
    927         n = cal.get(Calendar.MONTH) + 1;
    928         sb.setCharAt(5, (char)('0'+n%10));
    929         n /= 10;
    930         sb.setCharAt(4, (char)('0'+n%10));
    931 
    932         n = cal.get(Calendar.DAY_OF_MONTH);
    933         sb.setCharAt(7, (char)('0'+n%10));
    934         n /= 10;
    935         sb.setCharAt(6, (char)('0'+n%10));
    936 
    937         sb.setCharAt(8, 'T');
    938 
    939         n = cal.get(Calendar.HOUR_OF_DAY);
    940         sb.setCharAt(10, (char)('0'+n%10));
    941         n /= 10;
    942         sb.setCharAt(9, (char)('0'+n%10));
    943 
    944         n = cal.get(Calendar.MINUTE);
    945         sb.setCharAt(12, (char)('0'+n%10));
    946         n /= 10;
    947         sb.setCharAt(11, (char)('0'+n%10));
    948 
    949         n = cal.get(Calendar.SECOND);
    950         sb.setCharAt(14, (char)('0'+n%10));
    951         n /= 10;
    952         sb.setCharAt(13, (char)('0'+n%10));
    953 
    954         return sb.toString();
    955     }
    956 
    957     /**
    958      * @hide
    959      * @deprecated use {@link android.text.format.Time}
    960      */
    961     public static void assign(Calendar lval, Calendar rval)
    962     {
    963         // there should be a faster way.
    964         lval.clear();
    965         lval.setTimeInMillis(rval.getTimeInMillis());
    966     }
    967 
    968     /**
    969      * Formats a date or a time range according to the local conventions.
    970      * <p>
    971      * Note that this is a convenience method. Using it involves creating an
    972      * internal {@link java.util.Formatter} instance on-the-fly, which is
    973      * somewhat costly in terms of memory and time. This is probably acceptable
    974      * if you use the method only rarely, but if you rely on it for formatting a
    975      * large number of dates, consider creating and reusing your own
    976      * {@link java.util.Formatter} instance and use the version of
    977      * {@link #formatDateRange(Context, long, long, int) formatDateRange}
    978      * that takes a {@link java.util.Formatter}.
    979      *
    980      * @param context the context is required only if the time is shown
    981      * @param startMillis the start time in UTC milliseconds
    982      * @param endMillis the end time in UTC milliseconds
    983      * @param flags a bit mask of options See
    984      * {@link #formatDateRange(Context, Formatter, long, long, int, String) formatDateRange}
    985      * @return a string containing the formatted date/time range.
    986      */
    987     public static String formatDateRange(Context context, long startMillis,
    988             long endMillis, int flags) {
    989         Formatter f = new Formatter(new StringBuilder(50), Locale.getDefault());
    990         return formatDateRange(context, f, startMillis, endMillis, flags).toString();
    991     }
    992 
    993     /**
    994      * Formats a date or a time range according to the local conventions.
    995      * <p>
    996      * Note that this is a convenience method for formatting the date or
    997      * time range in the local time zone. If you want to specify the time
    998      * zone please use
    999      * {@link #formatDateRange(Context, Formatter, long, long, int, String) formatDateRange}.
   1000      *
   1001      * @param context the context is required only if the time is shown
   1002      * @param formatter the Formatter used for formatting the date range.
   1003      * Note: be sure to call setLength(0) on StringBuilder passed to
   1004      * the Formatter constructor unless you want the results to accumulate.
   1005      * @param startMillis the start time in UTC milliseconds
   1006      * @param endMillis the end time in UTC milliseconds
   1007      * @param flags a bit mask of options See
   1008      * {@link #formatDateRange(Context, Formatter, long, long, int, String) formatDateRange}
   1009      * @return a string containing the formatted date/time range.
   1010      */
   1011     public static Formatter formatDateRange(Context context, Formatter formatter, long startMillis,
   1012             long endMillis, int flags) {
   1013         return formatDateRange(context, formatter, startMillis, endMillis, flags, null);
   1014     }
   1015 
   1016     /**
   1017      * Formats a date or a time range according to the local conventions.
   1018      *
   1019      * <p>
   1020      * Example output strings (date formats in these examples are shown using
   1021      * the US date format convention but that may change depending on the
   1022      * local settings):
   1023      * <ul>
   1024      *   <li>10:15am</li>
   1025      *   <li>3:00pm - 4:00pm</li>
   1026      *   <li>3pm - 4pm</li>
   1027      *   <li>3PM - 4PM</li>
   1028      *   <li>08:00 - 17:00</li>
   1029      *   <li>Oct 9</li>
   1030      *   <li>Tue, Oct 9</li>
   1031      *   <li>October 9, 2007</li>
   1032      *   <li>Oct 9 - 10</li>
   1033      *   <li>Oct 9 - 10, 2007</li>
   1034      *   <li>Oct 28 - Nov 3, 2007</li>
   1035      *   <li>Dec 31, 2007 - Jan 1, 2008</li>
   1036      *   <li>Oct 9, 8:00am - Oct 10, 5:00pm</li>
   1037      *   <li>12/31/2007 - 01/01/2008</li>
   1038      * </ul>
   1039      *
   1040      * <p>
   1041      * The flags argument is a bitmask of options from the following list:
   1042      *
   1043      * <ul>
   1044      *   <li>FORMAT_SHOW_TIME</li>
   1045      *   <li>FORMAT_SHOW_WEEKDAY</li>
   1046      *   <li>FORMAT_SHOW_YEAR</li>
   1047      *   <li>FORMAT_NO_YEAR</li>
   1048      *   <li>FORMAT_SHOW_DATE</li>
   1049      *   <li>FORMAT_NO_MONTH_DAY</li>
   1050      *   <li>FORMAT_12HOUR</li>
   1051      *   <li>FORMAT_24HOUR</li>
   1052      *   <li>FORMAT_CAP_AMPM</li>
   1053      *   <li>FORMAT_NO_NOON</li>
   1054      *   <li>FORMAT_CAP_NOON</li>
   1055      *   <li>FORMAT_NO_MIDNIGHT</li>
   1056      *   <li>FORMAT_CAP_MIDNIGHT</li>
   1057      *   <li>FORMAT_UTC</li>
   1058      *   <li>FORMAT_ABBREV_TIME</li>
   1059      *   <li>FORMAT_ABBREV_WEEKDAY</li>
   1060      *   <li>FORMAT_ABBREV_MONTH</li>
   1061      *   <li>FORMAT_ABBREV_ALL</li>
   1062      *   <li>FORMAT_NUMERIC_DATE</li>
   1063      * </ul>
   1064      *
   1065      * <p>
   1066      * If FORMAT_SHOW_TIME is set, the time is shown as part of the date range.
   1067      * If the start and end time are the same, then just the start time is
   1068      * shown.
   1069      *
   1070      * <p>
   1071      * If FORMAT_SHOW_WEEKDAY is set, then the weekday is shown.
   1072      *
   1073      * <p>
   1074      * If FORMAT_SHOW_YEAR is set, then the year is always shown.
   1075      * If FORMAT_NO_YEAR is set, then the year is not shown.
   1076      * If neither FORMAT_SHOW_YEAR nor FORMAT_NO_YEAR are set, then the year
   1077      * is shown only if it is different from the current year, or if the start
   1078      * and end dates fall on different years.  If both are set,
   1079      * FORMAT_SHOW_YEAR takes precedence.
   1080      *
   1081      * <p>
   1082      * Normally the date is shown unless the start and end day are the same.
   1083      * If FORMAT_SHOW_DATE is set, then the date is always shown, even for
   1084      * same day ranges.
   1085      *
   1086      * <p>
   1087      * If FORMAT_NO_MONTH_DAY is set, then if the date is shown, just the
   1088      * month name will be shown, not the day of the month.  For example,
   1089      * "January, 2008" instead of "January 6 - 12, 2008".
   1090      *
   1091      * <p>
   1092      * If FORMAT_CAP_AMPM is set and 12-hour time is used, then the "AM"
   1093      * and "PM" are capitalized.  You should not use this flag
   1094      * because in some locales these terms cannot be capitalized, and in
   1095      * many others it doesn't make sense to do so even though it is possible.
   1096      *
   1097      * <p>
   1098      * If FORMAT_NO_NOON is set and 12-hour time is used, then "12pm" is
   1099      * shown instead of "noon".
   1100      *
   1101      * <p>
   1102      * If FORMAT_CAP_NOON is set and 12-hour time is used, then "Noon" is
   1103      * shown instead of "noon".  You should probably not use this flag
   1104      * because in many locales it will not make sense to capitalize
   1105      * the term.
   1106      *
   1107      * <p>
   1108      * If FORMAT_NO_MIDNIGHT is set and 12-hour time is used, then "12am" is
   1109      * shown instead of "midnight".
   1110      *
   1111      * <p>
   1112      * If FORMAT_CAP_MIDNIGHT is set and 12-hour time is used, then "Midnight"
   1113      * is shown instead of "midnight".  You should probably not use this
   1114      * flag because in many locales it will not make sense to capitalize
   1115      * the term.
   1116      *
   1117      * <p>
   1118      * If FORMAT_12HOUR is set and the time is shown, then the time is
   1119      * shown in the 12-hour time format. You should not normally set this.
   1120      * Instead, let the time format be chosen automatically according to the
   1121      * system settings. If both FORMAT_12HOUR and FORMAT_24HOUR are set, then
   1122      * FORMAT_24HOUR takes precedence.
   1123      *
   1124      * <p>
   1125      * If FORMAT_24HOUR is set and the time is shown, then the time is
   1126      * shown in the 24-hour time format. You should not normally set this.
   1127      * Instead, let the time format be chosen automatically according to the
   1128      * system settings. If both FORMAT_12HOUR and FORMAT_24HOUR are set, then
   1129      * FORMAT_24HOUR takes precedence.
   1130      *
   1131      * <p>
   1132      * If FORMAT_UTC is set, then the UTC time zone is used for the start
   1133      * and end milliseconds unless a time zone is specified. If a time zone
   1134      * is specified it will be used regardless of the FORMAT_UTC flag.
   1135      *
   1136      * <p>
   1137      * If FORMAT_ABBREV_TIME is set and 12-hour time format is used, then the
   1138      * start and end times (if shown) are abbreviated by not showing the minutes
   1139      * if they are zero.  For example, instead of "3:00pm" the time would be
   1140      * abbreviated to "3pm".
   1141      *
   1142      * <p>
   1143      * If FORMAT_ABBREV_WEEKDAY is set, then the weekday (if shown) is
   1144      * abbreviated to a 3-letter string.
   1145      *
   1146      * <p>
   1147      * If FORMAT_ABBREV_MONTH is set, then the month (if shown) is abbreviated
   1148      * to a 3-letter string.
   1149      *
   1150      * <p>
   1151      * If FORMAT_ABBREV_ALL is set, then the weekday and the month (if shown)
   1152      * are abbreviated to 3-letter strings.
   1153      *
   1154      * <p>
   1155      * If FORMAT_NUMERIC_DATE is set, then the date is shown in numeric format
   1156      * instead of using the name of the month.  For example, "12/31/2008"
   1157      * instead of "December 31, 2008".
   1158      *
   1159      * @param context the context is required only if the time is shown
   1160      * @param formatter the Formatter used for formatting the date range.
   1161      * Note: be sure to call setLength(0) on StringBuilder passed to
   1162      * the Formatter constructor unless you want the results to accumulate.
   1163      * @param startMillis the start time in UTC milliseconds
   1164      * @param endMillis the end time in UTC milliseconds
   1165      * @param flags a bit mask of options
   1166      * @param timeZone the time zone to compute the string in. Use null for local
   1167      * or if the FORMAT_UTC flag is being used.
   1168      *
   1169      * @return the formatter with the formatted date/time range appended to the string buffer.
   1170      */
   1171     public static Formatter formatDateRange(Context context, Formatter formatter, long startMillis,
   1172             long endMillis, int flags, String timeZone) {
   1173         Resources res = Resources.getSystem();
   1174         boolean showTime = (flags & FORMAT_SHOW_TIME) != 0;
   1175         boolean showWeekDay = (flags & FORMAT_SHOW_WEEKDAY) != 0;
   1176         boolean showYear = (flags & FORMAT_SHOW_YEAR) != 0;
   1177         boolean noYear = (flags & FORMAT_NO_YEAR) != 0;
   1178         boolean useUTC = (flags & FORMAT_UTC) != 0;
   1179         boolean abbrevWeekDay = (flags & (FORMAT_ABBREV_WEEKDAY | FORMAT_ABBREV_ALL)) != 0;
   1180         boolean abbrevMonth = (flags & (FORMAT_ABBREV_MONTH | FORMAT_ABBREV_ALL)) != 0;
   1181         boolean noMonthDay = (flags & FORMAT_NO_MONTH_DAY) != 0;
   1182         boolean numericDate = (flags & FORMAT_NUMERIC_DATE) != 0;
   1183 
   1184         // If we're getting called with a single instant in time (from
   1185         // e.g. formatDateTime(), below), then we can skip a lot of
   1186         // computation below that'd otherwise be thrown out.
   1187         boolean isInstant = (startMillis == endMillis);
   1188 
   1189         Time startDate;
   1190         if (timeZone != null) {
   1191             startDate = new Time(timeZone);
   1192         } else if (useUTC) {
   1193             startDate = new Time(Time.TIMEZONE_UTC);
   1194         } else {
   1195             startDate = new Time();
   1196         }
   1197         startDate.set(startMillis);
   1198 
   1199         Time endDate;
   1200         int dayDistance;
   1201         if (isInstant) {
   1202             endDate = startDate;
   1203             dayDistance = 0;
   1204         } else {
   1205             if (timeZone != null) {
   1206                 endDate = new Time(timeZone);
   1207             } else if (useUTC) {
   1208                 endDate = new Time(Time.TIMEZONE_UTC);
   1209             } else {
   1210                 endDate = new Time();
   1211             }
   1212             endDate.set(endMillis);
   1213             int startJulianDay = Time.getJulianDay(startMillis, startDate.gmtoff);
   1214             int endJulianDay = Time.getJulianDay(endMillis, endDate.gmtoff);
   1215             dayDistance = endJulianDay - startJulianDay;
   1216         }
   1217 
   1218         // If the end date ends at 12am at the beginning of a day,
   1219         // then modify it to make it look like it ends at midnight on
   1220         // the previous day.  This will allow us to display "8pm - midnight",
   1221         // for example, instead of "Nov 10, 8pm - Nov 11, 12am". But we only do
   1222         // this if it is midnight of the same day as the start date because
   1223         // for multiple-day events, an end time of "midnight on Nov 11" is
   1224         // ambiguous and confusing (is that midnight the start of Nov 11, or
   1225         // the end of Nov 11?).
   1226         // If we are not showing the time then also adjust the end date
   1227         // for multiple-day events.  This is to allow us to display, for
   1228         // example, "Nov 10 -11" for an event with a start date of Nov 10
   1229         // and an end date of Nov 12 at 00:00.
   1230         // If the start and end time are the same, then skip this and don't
   1231         // adjust the date.
   1232         if (!isInstant
   1233             && (endDate.hour | endDate.minute | endDate.second) == 0
   1234             && (!showTime || dayDistance <= 1)) {
   1235             endDate.monthDay -= 1;
   1236             endDate.normalize(true /* ignore isDst */);
   1237         }
   1238 
   1239         int startDay = startDate.monthDay;
   1240         int startMonthNum = startDate.month;
   1241         int startYear = startDate.year;
   1242 
   1243         int endDay = endDate.monthDay;
   1244         int endMonthNum = endDate.month;
   1245         int endYear = endDate.year;
   1246 
   1247         String startWeekDayString = "";
   1248         String endWeekDayString = "";
   1249         if (showWeekDay) {
   1250             String weekDayFormat = "";
   1251             if (abbrevWeekDay) {
   1252                 weekDayFormat = ABBREV_WEEKDAY_FORMAT;
   1253             } else {
   1254                 weekDayFormat = WEEKDAY_FORMAT;
   1255             }
   1256             startWeekDayString = startDate.format(weekDayFormat);
   1257             endWeekDayString = isInstant ? startWeekDayString : endDate.format(weekDayFormat);
   1258         }
   1259 
   1260         String startTimeString = "";
   1261         String endTimeString = "";
   1262         if (showTime) {
   1263             String startTimeFormat = "";
   1264             String endTimeFormat = "";
   1265             boolean force24Hour = (flags & FORMAT_24HOUR) != 0;
   1266             boolean force12Hour = (flags & FORMAT_12HOUR) != 0;
   1267             boolean use24Hour;
   1268             if (force24Hour) {
   1269                 use24Hour = true;
   1270             } else if (force12Hour) {
   1271                 use24Hour = false;
   1272             } else {
   1273                 use24Hour = DateFormat.is24HourFormat(context);
   1274             }
   1275             if (use24Hour) {
   1276                 startTimeFormat = endTimeFormat =
   1277                     res.getString(com.android.internal.R.string.hour_minute_24);
   1278             } else {
   1279                 boolean abbrevTime = (flags & (FORMAT_ABBREV_TIME | FORMAT_ABBREV_ALL)) != 0;
   1280                 boolean capAMPM = (flags & FORMAT_CAP_AMPM) != 0;
   1281                 boolean noNoon = (flags & FORMAT_NO_NOON) != 0;
   1282                 boolean capNoon = (flags & FORMAT_CAP_NOON) != 0;
   1283                 boolean noMidnight = (flags & FORMAT_NO_MIDNIGHT) != 0;
   1284                 boolean capMidnight = (flags & FORMAT_CAP_MIDNIGHT) != 0;
   1285 
   1286                 boolean startOnTheHour = startDate.minute == 0 && startDate.second == 0;
   1287                 boolean endOnTheHour = endDate.minute == 0 && endDate.second == 0;
   1288                 if (abbrevTime && startOnTheHour) {
   1289                     if (capAMPM) {
   1290                         startTimeFormat = res.getString(com.android.internal.R.string.hour_cap_ampm);
   1291                     } else {
   1292                         startTimeFormat = res.getString(com.android.internal.R.string.hour_ampm);
   1293                     }
   1294                 } else {
   1295                     if (capAMPM) {
   1296                         startTimeFormat = res.getString(com.android.internal.R.string.hour_minute_cap_ampm);
   1297                     } else {
   1298                         startTimeFormat = res.getString(com.android.internal.R.string.hour_minute_ampm);
   1299                     }
   1300                 }
   1301 
   1302                 // Don't waste time on setting endTimeFormat when
   1303                 // we're dealing with an instant, where we'll never
   1304                 // need the end point.  (It's the same as the start
   1305                 // point)
   1306                 if (!isInstant) {
   1307                     if (abbrevTime && endOnTheHour) {
   1308                         if (capAMPM) {
   1309                             endTimeFormat = res.getString(com.android.internal.R.string.hour_cap_ampm);
   1310                         } else {
   1311                             endTimeFormat = res.getString(com.android.internal.R.string.hour_ampm);
   1312                         }
   1313                     } else {
   1314                         if (capAMPM) {
   1315                             endTimeFormat = res.getString(com.android.internal.R.string.hour_minute_cap_ampm);
   1316                         } else {
   1317                             endTimeFormat = res.getString(com.android.internal.R.string.hour_minute_ampm);
   1318                         }
   1319                     }
   1320 
   1321                     if (endDate.hour == 12 && endOnTheHour && !noNoon) {
   1322                         if (capNoon) {
   1323                             endTimeFormat = res.getString(com.android.internal.R.string.Noon);
   1324                         } else {
   1325                             endTimeFormat = res.getString(com.android.internal.R.string.noon);
   1326                         }
   1327                     } else if (endDate.hour == 0 && endOnTheHour && !noMidnight) {
   1328                         if (capMidnight) {
   1329                             endTimeFormat = res.getString(com.android.internal.R.string.Midnight);
   1330                         } else {
   1331                             endTimeFormat = res.getString(com.android.internal.R.string.midnight);
   1332                         }
   1333                     }
   1334                 }
   1335 
   1336                 if (startDate.hour == 12 && startOnTheHour && !noNoon) {
   1337                     if (capNoon) {
   1338                         startTimeFormat = res.getString(com.android.internal.R.string.Noon);
   1339                     } else {
   1340                         startTimeFormat = res.getString(com.android.internal.R.string.noon);
   1341                     }
   1342                     // Don't show the start time starting at midnight.  Show
   1343                     // 12am instead.
   1344                 }
   1345             }
   1346 
   1347             startTimeString = startDate.format(startTimeFormat);
   1348             endTimeString = isInstant ? startTimeString : endDate.format(endTimeFormat);
   1349         }
   1350 
   1351         // Show the year if the user specified FORMAT_SHOW_YEAR or if
   1352         // the starting and end years are different from each other
   1353         // or from the current year.  But don't show the year if the
   1354         // user specified FORMAT_NO_YEAR.
   1355         if (showYear) {
   1356             // No code... just a comment for clarity.  Keep showYear
   1357             // on, as they enabled it with FORMAT_SHOW_YEAR.  This
   1358             // takes precedence over them setting FORMAT_NO_YEAR.
   1359         } else if (noYear) {
   1360             // They explicitly didn't want a year.
   1361             showYear = false;
   1362         } else if (startYear != endYear) {
   1363             showYear = true;
   1364         } else {
   1365             // Show the year if it's not equal to the current year.
   1366             Time currentTime = new Time();
   1367             currentTime.setToNow();
   1368             showYear = startYear != currentTime.year;
   1369         }
   1370 
   1371         String defaultDateFormat, fullFormat, dateRange;
   1372         if (numericDate) {
   1373             defaultDateFormat = res.getString(com.android.internal.R.string.numeric_date);
   1374         } else if (showYear) {
   1375             if (abbrevMonth) {
   1376                 if (noMonthDay) {
   1377                     defaultDateFormat = res.getString(com.android.internal.R.string.abbrev_month_year);
   1378                 } else {
   1379                     defaultDateFormat = res.getString(com.android.internal.R.string.abbrev_month_day_year);
   1380                 }
   1381             } else {
   1382                 if (noMonthDay) {
   1383                     defaultDateFormat = res.getString(com.android.internal.R.string.month_year);
   1384                 } else {
   1385                     defaultDateFormat = res.getString(com.android.internal.R.string.month_day_year);
   1386                 }
   1387             }
   1388         } else {
   1389             if (abbrevMonth) {
   1390                 if (noMonthDay) {
   1391                     defaultDateFormat = res.getString(com.android.internal.R.string.abbrev_month);
   1392                 } else {
   1393                     defaultDateFormat = res.getString(com.android.internal.R.string.abbrev_month_day);
   1394                 }
   1395             } else {
   1396                 if (noMonthDay) {
   1397                     defaultDateFormat = res.getString(com.android.internal.R.string.month);
   1398                 } else {
   1399                     defaultDateFormat = res.getString(com.android.internal.R.string.month_day);
   1400                 }
   1401             }
   1402         }
   1403 
   1404         if (showWeekDay) {
   1405             if (showTime) {
   1406                 fullFormat = res.getString(com.android.internal.R.string.wday1_date1_time1_wday2_date2_time2);
   1407             } else {
   1408                 fullFormat = res.getString(com.android.internal.R.string.wday1_date1_wday2_date2);
   1409             }
   1410         } else {
   1411             if (showTime) {
   1412                 fullFormat = res.getString(com.android.internal.R.string.date1_time1_date2_time2);
   1413             } else {
   1414                 fullFormat = res.getString(com.android.internal.R.string.date1_date2);
   1415             }
   1416         }
   1417 
   1418         if (noMonthDay && startMonthNum == endMonthNum && startYear == endYear) {
   1419             // Example: "January, 2008"
   1420             return formatter.format("%s", startDate.format(defaultDateFormat));
   1421         }
   1422 
   1423         if (startYear != endYear || noMonthDay) {
   1424             // Different year or we are not showing the month day number.
   1425             // Example: "December 31, 2007 - January 1, 2008"
   1426             // Or: "January - February, 2008"
   1427             String startDateString = startDate.format(defaultDateFormat);
   1428             String endDateString = endDate.format(defaultDateFormat);
   1429 
   1430             // The values that are used in a fullFormat string are specified
   1431             // by position.
   1432             return formatter.format(fullFormat,
   1433                     startWeekDayString, startDateString, startTimeString,
   1434                     endWeekDayString, endDateString, endTimeString);
   1435         }
   1436 
   1437         // Get the month, day, and year strings for the start and end dates
   1438         String monthFormat;
   1439         if (numericDate) {
   1440             monthFormat = NUMERIC_MONTH_FORMAT;
   1441         } else if (abbrevMonth) {
   1442             monthFormat =
   1443                 res.getString(com.android.internal.R.string.short_format_month);
   1444         } else {
   1445             monthFormat = MONTH_FORMAT;
   1446         }
   1447         String startMonthString = startDate.format(monthFormat);
   1448         String startMonthDayString = startDate.format(MONTH_DAY_FORMAT);
   1449         String startYearString = startDate.format(YEAR_FORMAT);
   1450 
   1451         String endMonthString = isInstant ? null : endDate.format(monthFormat);
   1452         String endMonthDayString = isInstant ? null : endDate.format(MONTH_DAY_FORMAT);
   1453         String endYearString = isInstant ? null : endDate.format(YEAR_FORMAT);
   1454 
   1455         if (startMonthNum != endMonthNum) {
   1456             // Same year, different month.
   1457             // Example: "October 28 - November 3"
   1458             // or: "Wed, Oct 31 - Sat, Nov 3, 2007"
   1459             // or: "Oct 31, 8am - Sat, Nov 3, 2007, 5pm"
   1460 
   1461             int index = 0;
   1462             if (showWeekDay) index = 1;
   1463             if (showYear) index += 2;
   1464             if (showTime) index += 4;
   1465             if (numericDate) index += 8;
   1466             int resId = sameYearTable[index];
   1467             fullFormat = res.getString(resId);
   1468 
   1469             // The values that are used in a fullFormat string are specified
   1470             // by position.
   1471             return formatter.format(fullFormat,
   1472                     startWeekDayString, startMonthString, startMonthDayString,
   1473                     startYearString, startTimeString,
   1474                     endWeekDayString, endMonthString, endMonthDayString,
   1475                     endYearString, endTimeString);
   1476         }
   1477 
   1478         if (startDay != endDay) {
   1479             // Same month, different day.
   1480             int index = 0;
   1481             if (showWeekDay) index = 1;
   1482             if (showYear) index += 2;
   1483             if (showTime) index += 4;
   1484             if (numericDate) index += 8;
   1485             int resId = sameMonthTable[index];
   1486             fullFormat = res.getString(resId);
   1487 
   1488             // The values that are used in a fullFormat string are specified
   1489             // by position.
   1490             return formatter.format(fullFormat,
   1491                     startWeekDayString, startMonthString, startMonthDayString,
   1492                     startYearString, startTimeString,
   1493                     endWeekDayString, endMonthString, endMonthDayString,
   1494                     endYearString, endTimeString);
   1495         }
   1496 
   1497         // Same start and end day
   1498         boolean showDate = (flags & FORMAT_SHOW_DATE) != 0;
   1499 
   1500         // If nothing was specified, then show the date.
   1501         if (!showTime && !showDate && !showWeekDay) showDate = true;
   1502 
   1503         // Compute the time string (example: "10:00 - 11:00 am")
   1504         String timeString = "";
   1505         if (showTime) {
   1506             // If the start and end time are the same, then just show the
   1507             // start time.
   1508             if (isInstant) {
   1509                 // Same start and end time.
   1510                 // Example: "10:15 AM"
   1511                 timeString = startTimeString;
   1512             } else {
   1513                 // Example: "10:00 - 11:00 am"
   1514                 String timeFormat = res.getString(com.android.internal.R.string.time1_time2);
   1515                 // Don't use the user supplied Formatter because the result will pollute the buffer.
   1516                 timeString = String.format(timeFormat, startTimeString, endTimeString);
   1517             }
   1518         }
   1519 
   1520         // Figure out which full format to use.
   1521         fullFormat = "";
   1522         String dateString = "";
   1523         if (showDate) {
   1524             dateString = startDate.format(defaultDateFormat);
   1525             if (showWeekDay) {
   1526                 if (showTime) {
   1527                     // Example: "10:00 - 11:00 am, Tue, Oct 9"
   1528                     fullFormat = res.getString(com.android.internal.R.string.time_wday_date);
   1529                 } else {
   1530                     // Example: "Tue, Oct 9"
   1531                     fullFormat = res.getString(com.android.internal.R.string.wday_date);
   1532                 }
   1533             } else {
   1534                 if (showTime) {
   1535                     // Example: "10:00 - 11:00 am, Oct 9"
   1536                     fullFormat = res.getString(com.android.internal.R.string.time_date);
   1537                 } else {
   1538                     // Example: "Oct 9"
   1539                     return formatter.format("%s", dateString);
   1540                 }
   1541             }
   1542         } else if (showWeekDay) {
   1543             if (showTime) {
   1544                 // Example: "10:00 - 11:00 am, Tue"
   1545                 fullFormat = res.getString(com.android.internal.R.string.time_wday);
   1546             } else {
   1547                 // Example: "Tue"
   1548                 return formatter.format("%s", startWeekDayString);
   1549             }
   1550         } else if (showTime) {
   1551             return formatter.format("%s", timeString);
   1552         }
   1553 
   1554         // The values that are used in a fullFormat string are specified
   1555         // by position.
   1556         return formatter.format(fullFormat, timeString, startWeekDayString, dateString);
   1557     }
   1558 
   1559     /**
   1560      * Formats a date or a time according to the local conventions. There are
   1561      * lots of options that allow the caller to control, for example, if the
   1562      * time is shown, if the day of the week is shown, if the month name is
   1563      * abbreviated, if noon is shown instead of 12pm, and so on. For the
   1564      * complete list of options, see the documentation for
   1565      * {@link #formatDateRange}.
   1566      * <p>
   1567      * Example output strings (date formats in these examples are shown using
   1568      * the US date format convention but that may change depending on the
   1569      * local settings):
   1570      * <ul>
   1571      *   <li>10:15am</li>
   1572      *   <li>3:00pm</li>
   1573      *   <li>3pm</li>
   1574      *   <li>3PM</li>
   1575      *   <li>08:00</li>
   1576      *   <li>17:00</li>
   1577      *   <li>noon</li>
   1578      *   <li>Noon</li>
   1579      *   <li>midnight</li>
   1580      *   <li>Midnight</li>
   1581      *   <li>Oct 31</li>
   1582      *   <li>Oct 31, 2007</li>
   1583      *   <li>October 31, 2007</li>
   1584      *   <li>10am, Oct 31</li>
   1585      *   <li>17:00, Oct 31</li>
   1586      *   <li>Wed</li>
   1587      *   <li>Wednesday</li>
   1588      *   <li>10am, Wed, Oct 31</li>
   1589      *   <li>Wed, Oct 31</li>
   1590      *   <li>Wednesday, Oct 31</li>
   1591      *   <li>Wed, Oct 31, 2007</li>
   1592      *   <li>Wed, October 31</li>
   1593      *   <li>10/31/2007</li>
   1594      * </ul>
   1595      *
   1596      * @param context the context is required only if the time is shown
   1597      * @param millis a point in time in UTC milliseconds
   1598      * @param flags a bit mask of formatting options
   1599      * @return a string containing the formatted date/time.
   1600      */
   1601     public static String formatDateTime(Context context, long millis, int flags) {
   1602         return formatDateRange(context, millis, millis, flags);
   1603     }
   1604 
   1605     /**
   1606      * @return a relative time string to display the time expressed by millis.  Times
   1607      * are counted starting at midnight, which means that assuming that the current
   1608      * time is March 31st, 0:30:
   1609      * <ul>
   1610      *   <li>"millis=0:10 today" will be displayed as "0:10"</li>
   1611      *   <li>"millis=11:30pm the day before" will be displayed as "Mar 30"</li>
   1612      * </ul>
   1613      * If the given millis is in a different year, then the full date is
   1614      * returned in numeric format (e.g., "10/12/2008").
   1615      *
   1616      * @param withPreposition If true, the string returned will include the correct
   1617      * preposition ("at 9:20am", "on 10/12/2008" or "on May 29").
   1618      */
   1619     public static CharSequence getRelativeTimeSpanString(Context c, long millis,
   1620             boolean withPreposition) {
   1621 
   1622         String result;
   1623         long now = System.currentTimeMillis();
   1624         long span = now - millis;
   1625 
   1626         synchronized (DateUtils.class) {
   1627             if (sNowTime == null) {
   1628                 sNowTime = new Time();
   1629             }
   1630 
   1631             if (sThenTime == null) {
   1632                 sThenTime = new Time();
   1633             }
   1634 
   1635             sNowTime.set(now);
   1636             sThenTime.set(millis);
   1637 
   1638             int prepositionId;
   1639             if (span < DAY_IN_MILLIS && sNowTime.weekDay == sThenTime.weekDay) {
   1640                 // Same day
   1641                 int flags = FORMAT_SHOW_TIME;
   1642                 result = formatDateRange(c, millis, millis, flags);
   1643                 prepositionId = R.string.preposition_for_time;
   1644             } else if (sNowTime.year != sThenTime.year) {
   1645                 // Different years
   1646                 int flags = FORMAT_SHOW_DATE | FORMAT_SHOW_YEAR | FORMAT_NUMERIC_DATE;
   1647                 result = formatDateRange(c, millis, millis, flags);
   1648 
   1649                 // This is a date (like "10/31/2008" so use the date preposition)
   1650                 prepositionId = R.string.preposition_for_date;
   1651             } else {
   1652                 // Default
   1653                 int flags = FORMAT_SHOW_DATE | FORMAT_ABBREV_MONTH;
   1654                 result = formatDateRange(c, millis, millis, flags);
   1655                 prepositionId = R.string.preposition_for_date;
   1656             }
   1657             if (withPreposition) {
   1658                 Resources res = c.getResources();
   1659                 result = res.getString(prepositionId, result);
   1660             }
   1661         }
   1662         return result;
   1663     }
   1664 
   1665     /**
   1666      * Convenience function to return relative time string without preposition.
   1667      * @param c context for resources
   1668      * @param millis time in milliseconds
   1669      * @return {@link CharSequence} containing relative time.
   1670      * @see #getRelativeTimeSpanString(Context, long, boolean)
   1671      */
   1672     public static CharSequence getRelativeTimeSpanString(Context c, long millis) {
   1673         return getRelativeTimeSpanString(c, millis, false /* no preposition */);
   1674     }
   1675 
   1676     private static Time sNowTime;
   1677     private static Time sThenTime;
   1678 }
   1679