1 * Copyright (C) 2016 and later: Unicode, Inc. and others. 2 * License & terms of use: http://www.unicode.org/copyright.html 3 ********************************************************************** 4 * Copyright (c) 2003-2014, International Business Machines 5 * Corporation and others. All Rights Reserved. 6 ********************************************************************** 7 * Author: Alan Liu 8 * Created: August 18 2003 9 * Since: ICU 2.8 10 ********************************************************************** 11 12 Note: this directory currently contains tzcode as of tzcode2014b.tar.gz 13 with localtime.c patches from tzcode2014b.tar.gz 14 15 16 ---------------------------------------------------------------------- 17 OVERVIEW 18 19 This file describes the tools in icu/source/tools/tzcode 20 21 The purpose of these tools is to process the zoneinfo or "Olson" time 22 zone database into a form usable by ICU4C (release 2.8 and later). 23 Unlike earlier releases, ICU4C 2.8 supports historical time zone 24 behavior, as well as the full set of Olson compatibility IDs. 25 26 References: 27 28 ICU4C: http://www.icu-project.org/ 29 Olson: ftp://ftp.iana.org/tz/releases/ 30 31 ---------------------------------------------------------------------- 32 ICU4C vs. ICU4J 33 34 For ICU releases >= 2.8, both ICU4C and ICU4J implement full 35 historical time zones, based on Olson data. The implementations in C 36 and Java are somewhat different. The C implementation is a 37 self-contained implementation, whereas ICU4J uses the underlying JDK 38 1.3 or 1.4 time zone implementation. 39 40 Older versions of ICU (C and Java <= 2.6) implement a "present day 41 snapshot". This only reflects current time zone behavior, without 42 historical variation. Furthermore, it lacks the full set of Olson 43 compatibility IDs. 44 45 ---------------------------------------------------------------------- 46 BACKGROUND 47 48 The zoneinfo or "Olson" time zone package is used by various systems 49 to describe the behavior of time zones. The package consists of 50 several parts. E.g.: 51 52 Index of ftp://ftp.iana.org/tz/releases/ 53 54 tzcode2014b.tar.gz 172 KB 3/25/2014 05:11:00 AM 55 tzdata2014b.tar.gz 216 KB 3/25/2014 05:11:00 AM 56 57 ICU only uses the tzdataYYYYV.tar.gz files, 58 where YYYY is the year and V is the version letter ('a'...'z'). 59 60 This directory has partial contents of tzcode checked into ICU 61 62 ---------------------------------------------------------------------- 63 HOWTO 64 65 0. Note, these instructions will only work on POSIX type systems. 66 67 1. Obtain the current versions of tzdataYYYYV.tar.gz (aka `tzdata') from 68 the FTP site given above. Either manually download or use wget: 69 70 $ cd {path_to}/icu/source/tools/tzcode 71 $ wget "ftp://ftp.iana.org/tz/releases/tzdata*.tar.gz" 72 73 2. Copy only one tzdata*.tar.gz file into the icu/source/tools/tzcode/ 74 directory (this directory). 75 76 *** Make sure you only have ONE FILE named tzdata*.tar.gz in the 77 directory. 78 79 3. Build ICU normally. You will see a notice "updating zoneinfo.txt..." 80 81 ### Following instructions for ICU maintainers only ### 82 83 4. Obtain the current version of tzcodeYYYY.tar.gz from the FTP site to 84 this directory. 85 86 5. Run make target "check-dump". This target extract makes the original 87 tzcode and compile the original tzdata with icu supplemental data 88 (icuzones). Then it makes zdump / icuzdump and dump all time 89 transitions for all ICU timezone to files under zdumpout / icuzdumpout 90 directory. When they produce different results, the target returns 91 the error. 92 93 6. Don't forget to check in the new zoneinfo64.txt (from its location at 94 {path_to}/icu/source/data/misc/zoneinfo64.txt) into SVN. 95 96
