43 lines
1.7 KiB
Plaintext
43 lines
1.7 KiB
Plaintext
src/timezone/README
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Timezone
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========
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This is a PostgreSQL adapted version of the timezone library from
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http://www.iana.org/time-zones
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The source code can be found at:
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ftp://ftp.iana.org/tz/releases/tzcode*.tar.gz
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The code is currently synced with release 2010c. There are many cosmetic
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(and not so cosmetic) differences from the original tzcode library, but
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diffs in the upstream version should usually be propagated to our version.
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The data files under data/ are an exact copy of the latest data set from:
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ftp://ftp.iana.org/tz/releases/tzdata*.tar.gz
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Since time zone rules change frequently in some parts of the world,
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we should endeavor to update the data files before each PostgreSQL
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release.
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While the files under data/ can just be duplicated when updating, manual
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effort is needed to update the time zone abbreviation lists under tznames/.
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These need to be changed whenever new abbreviations are invented or the
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UTC offset associated with an existing abbreviation changes. To detect
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if this has happened, after installing new files under data/ do
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gmake abbrevs.txt
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which will produce a file showing all abbreviations that are in current
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use according to the data/ files. Compare this to known_abbrevs.txt,
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which is the list that existed last time the tznames/ files were updated.
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Update tznames/ as seems appropriate, then replace known_abbrevs.txt
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in the same commit.
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When there has been a new release of Windows (probably including Service
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Packs), the list of matching timezones need to be updated. Run the
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script in src/tools/win32tzlist.pl on a Windows machine running this new
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release and apply any new timezones that it detects. Never remove any
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mappings in case they are removed in Windows, since we still need to
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match properly on the old version.
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