firebird/firebird-mirror
firebird/firebird-mirror
8
0
Fork 1
mirror of https://github.com/FirebirdSQL/firebird.git synced 2025-01-22 20:03:02 +01:00
Code Issues

Add section "Updating the time zone database" to documentation.

Browse Source
This commit is contained in:
Adriano dos Santos Fernandes 2018-07-05 13:08:14 -03:00
parent 9d84e12468
commit db60575bfb
1 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
doc/sql.extensions/README.time_zone.md
View File

@ -317,6 +317,16 @@ Returns:
2018-10-21 03:00:00.0000 GMT 2019-02-17 01:59:59.9999 GMT -180 60 -120
```
# Updating the time zone database
Time zones are often changed and when this happen it's convenient to update the time zone database as soon as possible.
Firebird stores `WITH TIME ZONE` values translated to UTC time. If a value is created with one time zone database and later that database is updated and the update changes the information in the range of a stored value, when reading that value it will be returned as a different than the one initially stored.
Firebird uses the [IANA time zone database](http://www.iana.org/time-zones) through the ICU library. ICU library present in Firebird kit (Windows) or present in OS (Linux, POSIX) sometimes has outdated time zone database.
Update procedure is described in that [ICU page](http://userguide.icu-project.org/datetime/timezone#TOC-Updating-the-Time-Zone-Data). The easiest way to update is downloading the `*.res` files in a directory and set `ICU_TIMEZONE_FILES_DIR` to point to it.
# Appendix: time zone regions