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