[tz] Format for Asia/Bangkok

[Paul Eggert]

On 9/10/21 1:00 AM, Danilo Spinella via tz wrote:
> I have noticed that the format for the zone Asia/Bangkok is shown as
> "+07" instead of Indochina Time (ICT), Western Indonesian Time (WIB) or
> Thailand Standard Time (THA). Is this because none of the above is
> standard?

Yes, as far as we know there is no widely-used English-language 
abbreviation for time in that timezone. Long ago when POSIX required an 
acronym for each time zone, I invented "ICT" to fill in the blank spot 
for Asia/Bangkok etc. After POSIX relaxed that requirement it was 
changed in tzdb to "+07" which is what it probably should have been in 
the first place.