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     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 **********************************************************************

    10 Note:  this directory currently contains tzcode as of tzcode2006h.tar.gz

    11    with localtime.c  patches from tzcode2006i.tar.gz

    14 ----------------------------------------------------------------------

    15 OVERVIEW

    17 This file describes the tools in icu/source/tools/tzcode

    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.

    24 References:

    26 ICU4C:  http://www.icu-project.org/

    27 Olson:  ftp://elsie.nci.nih.gov/pub/

    29 ----------------------------------------------------------------------

    30 ICU4C vs. ICU4J

    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.

    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.

    43 ----------------------------------------------------------------------

    44 BACKGROUND

    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.:

    50   Index of ftp://elsie.nci.nih.gov/pub/

    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

    63 ICU only uses the tzdataYYYYV.tar.gz files,

    64 where YYYY is the year and V is the version letter ('a'...'z').

    66 This directory has partial contents of tzcode checked into ICU

    68 ----------------------------------------------------------------------

    69 HOWTO

    71 0. Note, these instructions will only work on POSIX type systems.

    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:

    76    $ cd {path_to}/icu/source/tools/tzcode

    77    $ wget "ftp://elsie.nci.nih.gov/pub/tzdata*.tar.gz"

    79 2. Copy only one tzdata*.tar.gz file into the icu/source/tools/tzcode/

    80    directory (this directory).

    82    *** Make sure you only have ONE FILE named tzdata*.tar.gz in the

    83        directory.

    85 3. Build ICU normally. You will see a notice "updating zoneinfo.txt..."

    87 ### Following instructions for ICU maintainers only ###

    89 4. Obtain the current version of tzcodeYYYY.tar.gz from the FTP site to

    90    this directory.

    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.

    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.

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