michael@0: **********************************************************************
michael@0: * Copyright (c) 2003-2007, International Business Machines
michael@0: * Corporation and others.  All Rights Reserved.
michael@0: **********************************************************************
michael@0: * Author: Alan Liu
michael@0: * Created: August 18 2003
michael@0: * Since: ICU 2.8
michael@0: **********************************************************************
michael@0: 
michael@0: Note:  this directory currently contains tzcode as of tzcode2006h.tar.gz
michael@0:    with localtime.c  patches from tzcode2006i.tar.gz
michael@0: 
michael@0: 
michael@0: ----------------------------------------------------------------------
michael@0: OVERVIEW
michael@0: 
michael@0: This file describes the tools in icu/source/tools/tzcode
michael@0: 
michael@0: The purpose of these tools is to process the zoneinfo or "Olson" time
michael@0: zone database into a form usable by ICU4C (release 2.8 and later).
michael@0: Unlike earlier releases, ICU4C 2.8 supports historical time zone
michael@0: behavior, as well as the full set of Olson compatibility IDs.
michael@0: 
michael@0: References:
michael@0: 
michael@0: ICU4C:  http://www.icu-project.org/
michael@0: Olson:  ftp://elsie.nci.nih.gov/pub/
michael@0: 
michael@0: ----------------------------------------------------------------------
michael@0: ICU4C vs. ICU4J
michael@0: 
michael@0: For ICU releases >= 2.8, both ICU4C and ICU4J implement full
michael@0: historical time zones, based on Olson data.  The implementations in C
michael@0: and Java are somewhat different.  The C implementation is a
michael@0: self-contained implementation, whereas ICU4J uses the underlying JDK
michael@0: 1.3 or 1.4 time zone implementation.
michael@0: 
michael@0: Older versions of ICU (C and Java <= 2.6) implement a "present day
michael@0: snapshot".  This only reflects current time zone behavior, without
michael@0: historical variation.  Furthermore, it lacks the full set of Olson
michael@0: compatibility IDs.
michael@0: 
michael@0: ----------------------------------------------------------------------
michael@0: BACKGROUND
michael@0: 
michael@0: The zoneinfo or "Olson" time zone package is used by various systems
michael@0: to describe the behavior of time zones.  The package consists of
michael@0: several parts.  E.g.:
michael@0: 
michael@0:   Index of ftp://elsie.nci.nih.gov/pub/
michael@0: 
michael@0:   classictzcode.tar.gz    65 KB        12/10/1994    12:00:00 AM
michael@0:   classictzdata.tar.gz    67 KB        12/10/1994    12:00:00 AM
michael@0:   e5+57.tar.gz            2909 KB      3/22/1993     12:00:00 AM
michael@0:   iso8601.ps.gz           16 KB        7/27/1996     12:00:00 AM
michael@0:   leastsq.xls             49 KB        4/24/1997     12:00:00 AM
michael@0:   ltroff.tar.gz           36 KB        7/16/1993     12:00:00 AM
michael@0:   pi.shar.gz              4 KB         3/9/1994      12:00:00 AM
michael@0:   tzarchive.gz            3412 KB      8/18/2003     4:00:00 AM
michael@0:   tzcode2003a.tar.gz      98 KB        3/24/2003     2:32:00 PM
michael@0:   tzdata2003a.tar.gz      132 KB       3/24/2003     2:32:00 PM
michael@0: 
michael@0: ICU only uses the tzdataYYYYV.tar.gz files,
michael@0: where YYYY is the year and V is the version letter ('a'...'z').
michael@0: 
michael@0: This directory has partial contents of tzcode checked into ICU
michael@0: 
michael@0: ----------------------------------------------------------------------
michael@0: HOWTO
michael@0: 
michael@0: 0. Note, these instructions will only work on POSIX type systems.
michael@0: 
michael@0: 1. Obtain the current versions of tzdataYYYYV.tar.gz (aka `tzdata') from
michael@0:    the FTP site given above.  Either manually download or use wget:
michael@0: 
michael@0:    $ cd {path_to}/icu/source/tools/tzcode
michael@0:    $ wget "ftp://elsie.nci.nih.gov/pub/tzdata*.tar.gz"
michael@0: 
michael@0: 2. Copy only one tzdata*.tar.gz file into the icu/source/tools/tzcode/
michael@0:    directory (this directory).
michael@0: 
michael@0:    *** Make sure you only have ONE FILE named tzdata*.tar.gz in the
michael@0:        directory.
michael@0: 
michael@0: 3. Build ICU normally. You will see a notice "updating zoneinfo.txt..."
michael@0: 
michael@0: ### Following instructions for ICU maintainers only ###
michael@0: 
michael@0: 4. Obtain the current version of tzcodeYYYY.tar.gz from the FTP site to
michael@0:    this directory.
michael@0: 
michael@0: 5. Run make target "check-dump".  This target extract makes the original
michael@0:    tzcode and compile the original tzdata with icu supplemental data
michael@0:    (icuzones).  Then it makes zdump / icuzdump and dump all time
michael@0:    transitions for all ICU timezone to files under zdumpout / icuzdumpout
michael@0:    directory.  When they produce different results, the target returns
michael@0:    the error.
michael@0: 
michael@0: 6. Don't forget to check in the new zoneinfo.txt (from its location at
michael@0:    {path_to}/icu/source/data/misc/zoneinfo.txt) into SVN.
michael@0: