Rename the city (calcutta) to kolkata in India

[vkante]

Calcutta is no longer a city in India now. It's name was changed to Kolkata 20 years ago. please correct Asia/Calcutta to Asia/Kolkata.

https://github.com/manuelmhtr/countries-and-timezones/blob/dev/src/data.json#L572

[AlyoshaVasilieva]

Asia/Kolkata is already in the data:

countries-and-timezones/src/data.json

Line 603 in 710ae31

"Asia/Kolkata": { "u": 330, "c": ["IN"] },

Asia/Calcutta is an alias to it.

tzdb contains backward compatibility aliases, see file backward in the original tzdb data which contains a link from Asia/Calcutta to Asia/Kolkata.

https://data.iana.org/time-zones/theory.html#naming

If a name is changed, put its old spelling in the 'backward' file as a link to the new spelling. This means old spellings will continue to work. Ordinarily a name change should occur only in the rare case when a location's consensus English-language spelling changes; for example, in 2008 Asia/Calcutta was renamed to Asia/Kolkata due to long-time widespread use of the new city name instead of the old.