1 #ifndef TZFILE_H 2 3 #define TZFILE_H 4 5 /* 6 ** This file is in the public domain, so clarified as of 7 ** 1996-06-05 by Arthur David Olson. 8 */ 9 10 /* 11 ** This header is for use ONLY with the time conversion code. 12 ** There is no guarantee that it will remain unchanged, 13 ** or that it will remain at all. 14 ** Do NOT copy it to any system include directory. 15 ** Thank you! 16 */ 17 18 /* 19 ** Information about time zone files. 20 */ 21 22 #ifndef TZDIR 23 #define TZDIR "/usr/local/etc/zoneinfo" /* Time zone object file directory */ 24 #endif /* !defined TZDIR */ 25 26 #ifndef TZDEFAULT 27 #define TZDEFAULT "localtime" 28 #endif /* !defined TZDEFAULT */ 29 30 #ifndef TZDEFRULES 31 #define TZDEFRULES "posixrules" 32 #endif /* !defined TZDEFRULES */ 33 34 /* 35 ** Each file begins with. . . 36 */ 37 38 #define TZ_MAGIC "TZif" 39 40 struct tzhead { 41 char tzh_magic[4]; /* TZ_MAGIC */ 42 char tzh_version[1]; /* '\0' or '2' or '3' as of 2013 */ 43 char tzh_reserved[15]; /* reserved--must be zero */ 44 char tzh_ttisgmtcnt[4]; /* coded number of trans. time flags */ 45 char tzh_ttisstdcnt[4]; /* coded number of trans. time flags */ 46 char tzh_leapcnt[4]; /* coded number of leap seconds */ 47 char tzh_timecnt[4]; /* coded number of transition times */ 48 char tzh_typecnt[4]; /* coded number of local time types */ 49 char tzh_charcnt[4]; /* coded number of abbr. chars */ 50 }; 51 52 /* 53 ** . . .followed by. . . 54 ** 55 ** tzh_timecnt (char [4])s coded transition times a la time(2) 56 ** tzh_timecnt (unsigned char)s types of local time starting at above 57 ** tzh_typecnt repetitions of 58 ** one (char [4]) coded UT offset in seconds 59 ** one (unsigned char) used to set tm_isdst 60 ** one (unsigned char) that's an abbreviation list index 61 ** tzh_charcnt (char)s '\0'-terminated zone abbreviations 62 ** tzh_leapcnt repetitions of 63 ** one (char [4]) coded leap second transition times 64 ** one (char [4]) total correction after above 65 ** tzh_ttisstdcnt (char)s indexed by type; if TRUE, transition 66 ** time is standard time, if FALSE, 67 ** transition time is wall clock time 68 ** if absent, transition times are 69 ** assumed to be wall clock time 70 ** tzh_ttisgmtcnt (char)s indexed by type; if TRUE, transition 71 ** time is UT, if FALSE, 72 ** transition time is local time 73 ** if absent, transition times are 74 ** assumed to be local time 75 */ 76 77 /* 78 ** If tzh_version is '2' or greater, the above is followed by a second instance 79 ** of tzhead and a second instance of the data in which each coded transition 80 ** time uses 8 rather than 4 chars, 81 ** then a POSIX-TZ-environment-variable-style string for use in handling 82 ** instants after the last transition time stored in the file 83 ** (with nothing between the newlines if there is no POSIX representation for 84 ** such instants). 85 ** 86 ** If tz_version is '3' or greater, the above is extended as follows. 87 ** First, the POSIX TZ string's hour offset may range from -167 88 ** through 167 as compared to the POSIX-required 0 through 24. 89 ** Second, its DST start time may be January 1 at 00:00 and its stop 90 ** time December 31 at 24:00 plus the difference between DST and 91 ** standard time, indicating DST all year. 92 */ 93 94 /* 95 ** In the current implementation, "tzset()" refuses to deal with files that 96 ** exceed any of the limits below. 97 */ 98 99 #ifndef TZ_MAX_TIMES 100 #define TZ_MAX_TIMES 2000 101 #endif /* !defined TZ_MAX_TIMES */ 102 103 #ifndef TZ_MAX_TYPES 104 /* This must be at least 17 for Europe/Samara and Europe/Vilnius. */ 105 #define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */ 106 #endif /* !defined TZ_MAX_TYPES */ 107 108 #ifndef TZ_MAX_CHARS 109 #define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */ 110 /* (limited by what unsigned chars can hold) */ 111 #endif /* !defined TZ_MAX_CHARS */ 112 113 #ifndef TZ_MAX_LEAPS 114 #define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */ 115 #endif /* !defined TZ_MAX_LEAPS */ 116 117 #define SECSPERMIN 60 118 #define MINSPERHOUR 60 119 #define HOURSPERDAY 24 120 #define DAYSPERWEEK 7 121 #define DAYSPERNYEAR 365 122 #define DAYSPERLYEAR 366 123 #define SECSPERHOUR (SECSPERMIN * MINSPERHOUR) 124 #define SECSPERDAY ((int_fast32_t) SECSPERHOUR * HOURSPERDAY) 125 #define MONSPERYEAR 12 126 127 #define TM_SUNDAY 0 128 #define TM_MONDAY 1 129 #define TM_TUESDAY 2 130 #define TM_WEDNESDAY 3 131 #define TM_THURSDAY 4 132 #define TM_FRIDAY 5 133 #define TM_SATURDAY 6 134 135 #define TM_JANUARY 0 136 #define TM_FEBRUARY 1 137 #define TM_MARCH 2 138 #define TM_APRIL 3 139 #define TM_MAY 4 140 #define TM_JUNE 5 141 #define TM_JULY 6 142 #define TM_AUGUST 7 143 #define TM_SEPTEMBER 8 144 #define TM_OCTOBER 9 145 #define TM_NOVEMBER 10 146 #define TM_DECEMBER 11 147 148 #define TM_YEAR_BASE 1900 149 150 #define EPOCH_YEAR 1970 151 #define EPOCH_WDAY TM_THURSDAY 152 153 #define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0)) 154 155 /* 156 ** Since everything in isleap is modulo 400 (or a factor of 400), we know that 157 ** isleap(y) == isleap(y % 400) 158 ** and so 159 ** isleap(a + b) == isleap((a + b) % 400) 160 ** or 161 ** isleap(a + b) == isleap(a % 400 + b % 400) 162 ** This is true even if % means modulo rather than Fortran remainder 163 ** (which is allowed by C89 but not C99). 164 ** We use this to avoid addition overflow problems. 165 */ 166 167 #define isleap_sum(a, b) isleap((a) % 400 + (b) % 400) 168 169 #endif /* !defined TZFILE_H */ 170
