pszegheo@itnnetworks.com writes:
> "HDT" time zone is not recognized by PostreSQL 9.5
> Neither are the more modern HADT and HAST time zones recognized by PostreSQL
> 9.5
The IANA timezone database does not think that either HAST or HDST have
ever been in common use, and HDT hasn't been in use since 1945:
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Pacific/Honolulu -10:31:26 - LMT 1896 Jan 13 12:00
-10:30 - HST 1933 Apr 30 2:00
-10:30 1:00 HDT 1933 May 21 12:00
-10:30 - HST 1942 Feb 9 2:00
-10:30 1:00 HDT 1945 Sep 30 2:00
-10:30 - HST 1947 Jun 8 2:00
-10:00 - HST
We generally avoid including nonstandard abbreviations in PG's default
timezone abbreviations list, since they seem more likely to allow garbage
data to be entered than to be useful. Of course, you can set up your own
abbreviation list if you wish to use specific additional abbreviations.
See
https://www.postgresql.org/docs/9.5/static/datetime-config-files.html
regards, tom lane