| src/timezone/README |
| |
| Timezone |
| ======== |
| |
| This is a PostgreSQL adapted version of the timezone library from: |
| |
| ftp://elsie.nci.nih.gov/pub/tzcode*.tar.gz |
| |
| The code is currently synced with release 2010c. There are many cosmetic |
| (and not so cosmetic) differences from the original tzcode library, but |
| diffs in the upstream version should usually be propagated to our version. |
| |
| The data files under data/ are an exact copy of the latest data set from: |
| |
| ftp://elsie.nci.nih.gov/pub/tzdata*.tar.gz |
| |
| Since time zone rules change frequently in some parts of the world, |
| we should endeavor to update the data files before each PostgreSQL |
| release. |
| |
| At each update, we should check if time zone offsets have changed. |
| Just search for the current or previous year and see what has changed. |
| Sometimes a country changes its time zone offsets, for example Georgia |
| in 2004. Just grepping in the zic database files for 2004 is enough to |
| spot such a change. Then the files under tznames/ should be updated. |
| |
| When there has been a new release of Windows (probably including Service |
| Packs), the list of matching timezones need to be updated. Run the |
| script in src/tools/win32tzlist.pl on a Windows machine running this new |
| release and apply any new timezones that it detects. Never remove any |
| mappings in case they are removed in Windows, since we still need to |
| match properly on the old version. |