Re: Doubt on pg_timezone_names and pg_timezone_abbrevs

On Tue, Apr 1, 2025 at 9:28 AM David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>
wrote:

> On Mon, Mar 31, 2025 at 8:39 PM Jayadevan M <maymala(dot)jayadevan(at)gmail(dot)com>
> wrote:
>
>> Hello PG members,
>> I used 'IST' in a query like this - * (timestamp_hour) at time zone
>> 'IST' time_ist *and did not get the expected output - timestamp in
>> Indian Standard Time. So I queried the 2 views that provide timezone info
>> and did not really understand the abbrev column.
>> select name, abbrev, utc_offset from pg_timezone_names where abbrev =
>> 'IST' ;
>>
>
> Since the S and T are non-location specific you get 26 different timezone
> abbreviations to choose from. That wasn't enough for the world. So IST is
> non-unique; and for historical reasons Ireland (Eire, which contains
> Dublin) is given default priority.
>
>
>> name | abbrev | utc_offset
>> ---------------+--------+------------
>> Eire | IST | 01:00:00
>> Asia/Kolkata | IST | 05:30:00
>> Asia/Calcutta | IST | 05:30:00
>> Europe/Dublin | IST | 01:00:00
>>
>
> Suggest you adapt to using ISO names (the name column above) for
> timezones; which are long enough and location-specific enough to be
> unique. In your case, pick your preferred spelling of Calcutta I suppose.
>
> Thank you. I used Calcutta.
Regards,
Jayadevan