]> git.saurik.com Git - apple/icu.git/blob - icuSources/tools/tzcode/readme.txt
ICU-461.12.tar.gz
[apple/icu.git] / icuSources / tools / tzcode / readme.txt
1 **********************************************************************
2 * Copyright (c) 2003-2007, 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 tzcode2006h.tar.gz
11 with localtime.c patches from tzcode2006i.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://elsie.nci.nih.gov/pub/
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://elsie.nci.nih.gov/pub/
51
52 classictzcode.tar.gz 65 KB 12/10/1994 12:00:00 AM
53 classictzdata.tar.gz 67 KB 12/10/1994 12:00:00 AM
54 e5+57.tar.gz 2909 KB 3/22/1993 12:00:00 AM
55 iso8601.ps.gz 16 KB 7/27/1996 12:00:00 AM
56 leastsq.xls 49 KB 4/24/1997 12:00:00 AM
57 ltroff.tar.gz 36 KB 7/16/1993 12:00:00 AM
58 pi.shar.gz 4 KB 3/9/1994 12:00:00 AM
59 tzarchive.gz 3412 KB 8/18/2003 4:00:00 AM
60 tzcode2003a.tar.gz 98 KB 3/24/2003 2:32:00 PM
61 tzdata2003a.tar.gz 132 KB 3/24/2003 2:32:00 PM
62
63 ICU only uses the tzdataYYYYV.tar.gz files,
64 where YYYY is the year and V is the version letter ('a'...'z').
65
66 This directory has partial contents of tzcode checked into ICU
67
68 ----------------------------------------------------------------------
69 HOWTO
70
71 0. Note, these instructions will only work on POSIX type systems.
72
73 1. Obtain the current versions of tzdataYYYYV.tar.gz (aka `tzdata') from
74 the FTP site given above. Either manually download or use wget:
75
76 $ cd {path_to}/icu/source/tools/tzcode
77 $ wget "ftp://elsie.nci.nih.gov/pub/tzdata*.tar.gz"
78
79 2. Copy only one tzdata*.tar.gz file into the icu/source/tools/tzcode/
80 directory (this directory).
81
82 *** Make sure you only have ONE FILE named tzdata*.tar.gz in the
83 directory.
84
85 3. Build ICU normally. You will see a notice "updating zoneinfo.txt..."
86
87 ### Following instructions for ICU maintainers only ###
88
89 4. Obtain the current version of tzcodeYYYY.tar.gz from the FTP site to
90 this directory.
91
92 5. Run make target "check-dump". This target extract makes the original
93 tzcode and compile the original tzdata with icu supplemental data
94 (icuzones). Then it makes zdump / icuzdump and dump all time
95 transitions for all ICU timezone to files under zdumpout / icuzdumpout
96 directory. When they produce different results, the target returns
97 the error.
98
99 6. Don't forget to check in the new zoneinfo.txt (from its location at
100 {path_to}/icu/source/data/misc/zoneinfo.txt) into SVN.
101