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* Copyright (C) 2016 and later: Unicode, Inc. and others.
* License & terms of use:
* Copyright (c) 2003-2014, International Business Machines
* Corporation and others. All Rights Reserved.
* Author: Alan Liu
* Created: August 18 2003
* Since: ICU 2.8
Note: this directory currently contains tzcode as of tzcode2014b.tar.gz
with localtime.c patches from tzcode2014b.tar.gz
This file describes the tools in icu/source/tools/tzcode
The purpose of these tools is to process the zoneinfo or "Olson" time
zone database into a form usable by ICU4C (release 2.8 and later).
Unlike earlier releases, ICU4C 2.8 supports historical time zone
behavior, as well as the full set of Olson compatibility IDs.
For ICU releases >= 2.8, both ICU4C and ICU4J implement full
historical time zones, based on Olson data. The implementations in C
and Java are somewhat different. The C implementation is a
self-contained implementation, whereas ICU4J uses the underlying JDK
1.3 or 1.4 time zone implementation.
Older versions of ICU (C and Java <= 2.6) implement a "present day
snapshot". This only reflects current time zone behavior, without
historical variation. Furthermore, it lacks the full set of Olson
compatibility IDs.
The zoneinfo or "Olson" time zone package is used by various systems
to describe the behavior of time zones. The package consists of
several parts. E.g.:
Index of
tzcode2014b.tar.gz 172 KB 3/25/2014 05:11:00 AM
tzdata2014b.tar.gz 216 KB 3/25/2014 05:11:00 AM
ICU only uses the tzdataYYYYV.tar.gz files,
where YYYY is the year and V is the version letter ('a'...'z').
This directory has partial contents of tzcode checked into ICU
0. Note, these instructions will only work on POSIX type systems.
1. Obtain the current versions of tzdataYYYYV.tar.gz (aka `tzdata') from
the FTP site given above. Either manually download or use wget:
$ cd {path_to}/icu/source/tools/tzcode
$ wget "*.tar.gz"
2. Copy only one tzdata*.tar.gz file into the icu/source/tools/tzcode/
directory (this directory).
*** Make sure you only have ONE FILE named tzdata*.tar.gz in the
3. Build ICU normally. You will see a notice "updating zoneinfo.txt..."
### Following instructions for ICU maintainers only ###
4. Obtain the current version of tzcodeYYYY.tar.gz from the FTP site to
this directory.
5. Run make target "check-dump". This target extract makes the original
tzcode and compile the original tzdata with icu supplemental data
(icuzones). Then it makes zdump / icuzdump and dump all time
transitions for all ICU timezone to files under zdumpout / icuzdumpout
directory. When they produce different results, the target returns
the error.
6. Don't forget to check in the new zoneinfo64.txt (from its location at
{path_to}/icu/source/data/misc/zoneinfo64.txt) into SVN.