Relation between Time Zone Abbreviation and Offset in Asia

Dear Tzdata Maintainers, Is it historically appeared in Asia, that several Locations have Offset only instead of Time Zone Abbreviation? I mean next location: Bangkok<https://www.timeanddate.com/time/zone/thailand/bangkok> from Thailand<https://www.timeanddate.com/time/zone/thailand> which is related with Vientiane<https://www.timeanddate.com/time/zone/laos/vientiane> from Laos<https://www.timeanddate.com/time/zone/laos> and Phnom Penh<https://www.timeanddate.com/time/zone/cambodia/phnom-penh> from Cambodia<https://www.timeanddate.com/time/zone/cambodia> - all of them is in Indochina Time<https://www.timeanddate.com/time/zones/ict>, but in repository for file asia they have only offset: https://github.com/eggert/tz/blob/main/asia#L3823 I don't know is it issue or typo, cause I didn't find any info when this Abbreviation was added https://en.wikipedia.org/wiki/UTC%2B07:00 For our customers, I added this step before compiling tzdata sources: # set Asia/Bangkok for Thailand to use name instead of digits in timezone, affecting on Asia/Vientiane for Laos and Asia/Phnom_Penh for Cambodia sed -i -e '/# Thailand/,/Vientiane/s/+07/ICT/' $(pwd)/asia but maybe it doesn't require and you will add corresponding changes in the main source code. BTW, during my investigation, I observed that several time zones have same behavior, ex.: Tajikistan<timeanddate.com/time/zone/tajikistan> - Asia/Dushanbe<https://www.timeanddate.com/time/zone/tajikistan/dushanbe> - TJT - Tajikistan Time<https://www.timeanddate.com/time/zones/tjt> https://github.com/eggert/tz/blob/main/asia#L3817 Turkmenistan<https://www.timeanddate.com/time/zone/turkmenistan> - Asia/Ashgabat<https://www.timeanddate.com/time/zone/turkmenistan/ashgabat> - TMT - Turkmenistan Time<https://www.timeanddate.com/time/zones/tmt> https://github.com/eggert/tz/blob/main/asia#L3834 United Arab Emirates<https://www.timeanddate.com/time/zone/united-arab-emirates> - Asia/Dubai<https://www.timeanddate.com/time/zone/united-arab-emirates/dubai> - GST - Gulf Standard Time<https://www.timeanddate.com/time/zones/gst> https://github.com/eggert/tz/blob/main/asia#L3839 Uzbekistan - Asia/Samarkand | Asia/Tashkent - UZT - Uzbekistan Time<https://www.timeanddate.com/time/zones/uzt> https://github.com/eggert/tz/blob/main/asia#L3851 Vietnam - Asia/Ho_Chi_Minh - ICT - Indochina Time<https://www.timeanddate.com/time/zones/ict> https://github.com/eggert/tz/blob/main/asia#L3920 Sri Lanka - Asia/Colombo - IST - India Standard Time<https://www.timeanddate.com/time/zones/ist> https://github.com/eggert/tz/blob/main/asia#L3645 Singapore - Asia/Singapore - SGT - Singapore Time<https://www.timeanddate.com/time/zones/sgt> https://github.com/eggert/tz/blob/main/asia#L3581 Saudi Arabia - Asia/Riyadh - AST - Arabia Standard Time<https://www.timeanddate.com/time/zones/ast-arabia> https://github.com/eggert/tz/blob/main/asia#L3565 Qatar - Asia/Qatar - AST - Arabia Standard Time<https://www.timeanddate.com/time/zones/ast-arabia> https://github.com/eggert/tz/blob/main/asia#L3518 Please give me explanation of this, is it correct to use Offset instead of Abbreviation or it will be fixed in future? Best regards, [cid:image001.jpg@01D72579.B94CFD20] Evgheni Antropov Software R&D Engineer +373 22 404 665 www.addgrup.com<http://www.addgrup.com/>

On 3/30/21 6:26 AM, Evgheni Antropov via tz wrote:
is it correct to use Offset instead of Abbreviation or it will be fixed in future?
The offset is intended. I invented the abbreviation "ICT" in 1993: https://github.com/eggert/tz/commit/61315cadc3d0e8b4ef559539502a606cf58fc0f7 Back then, POSIX required alphabetic abbreviations and I thought it better to be consistent with POSIX so I invented abbreviations all over the world to fill in the blanks. However, I was uncomfortable with tzdb inventing rather than describing usage. In 2001 POSIX was changed to allow numeric abbreviations and eventually (in version 2017a) tzdb was changed to use numeric abbreviations instead of the invented alphabetic ones. This change is described in the NEWS file, and tzdb's current practice for abbreviations is described here: https://data.iana.org/time-zones/theory.html#abbreviations
participants (2)
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Evgheni Antropov
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Paul Eggert