The changes are as follows:
• Fix one day offset in all western zones.
• Correct CST from -64800 to -21600 and CDT from -68400 to -18000.
• Disambiguate PST in favor of -28000 over +28000.
• Add GMT, UTC, WET, previously excluded for being at offset 0.
• Add ACDT, AEDT, AKST, MET, MSK, NST, NZDT, PKT, which the previous
code did not find.
• Remove numbered abbreviations -12, …, +14, which are unnecessary.
• Remove MSD and PKST, which are no longer used.
Hardcode the dict and verify it with a test, so that future
discrepancies won’t go silently unnoticed.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
While working on shifting toward native browser time zone APIs
(#16451), it was found that all but very recent Chrome and Node
versions reject certain legacy timezone aliases like US/Pacific
(https://crbug.com/364374).
For now, we only canonicalize the timezone property returned in user
objects and not the timezone setting itself.
Signed-off-by: Anders Kaseorg <anders@zulip.com>