********************************************************************** * Copyright (c) 2003-2006, 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 tzcode2006h.tar.gz with localtime.c patches from tzcode2006i.tar.gz ---------------------------------------------------------------------- OVERVIEW 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. References: ICU4C: http://icu.sourceforge.net/ Olson: ftp://elsie.nci.nih.gov/pub/ ---------------------------------------------------------------------- ICU4C vs. ICU4J 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. ---------------------------------------------------------------------- BACKGROUND 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 ftp://elsie.nci.nih.gov/pub/ classictzcode.tar.gz 65 KB 12/10/1994 12:00:00 AM classictzdata.tar.gz 67 KB 12/10/1994 12:00:00 AM e5+57.tar.gz 2909 KB 3/22/1993 12:00:00 AM iso8601.ps.gz 16 KB 7/27/1996 12:00:00 AM leastsq.xls 49 KB 4/24/1997 12:00:00 AM ltroff.tar.gz 36 KB 7/16/1993 12:00:00 AM pi.shar.gz 4 KB 3/9/1994 12:00:00 AM tzarchive.gz 3412 KB 8/18/2003 4:00:00 AM tzcode2003a.tar.gz 98 KB 3/24/2003 2:32:00 PM tzdata2003a.tar.gz 132 KB 3/24/2003 2:32:00 PM 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 ---------------------------------------------------------------------- HOWTO 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 "ftp://elsie.nci.nih.gov/pub/tzdata*.tar.gz" 2. copy only one tzdata*.tar.gz file into the icu/source/data/in/ directory (you may have to create this directory) *** Make sure you only have ONE FILE named tzdata*.tar.gz in the directory. 3. Build ICU normally. You will see a notice "updating zoneinfo.txt..." 4. For ICU maintainers, don't forget to check in the new zoneinfo.txt (from its location at {path_to}/icu/source/data/misc/zoneinfo.txt) into CVS.