Is there a problem with the name of India's timezone in Chrome?

Question

Wikipedia states that

The IANA time zone database contains only one zone pertaining to India, namely Asia/Kolkata.

When checking the authoritative source mentioned above, the timezone assigned to India is indeed Asia/Kolkata.

This does not seem to be the case, however, in the timezones provided by my Chrome browser (Version 120):

console.log(Intl.supportedValuesOf("timeZone").filter(x => x.includes('Asia/')))

There is no Asia/Kolkata but there is a Asia/Calcutta, the name of Kolkata until 2001.

Firefox reports Asia/Kolkata.

Is there a particular reason for this behaviour in Chrome?

Answer 1

I can't tell you the reason¹, but can tell you both seem to work (using my own 'es-date-fiddler'-library (see GitHub)).

Also: both Kolkata and Calcutta are listed in https://cloud.google.com/looker/docs/reference/param-view-timezone-values. And in Firefox Asia/Calcutta still works too.

Maybe it's something to file at Google issue tracker

¹ Both of the timeZones seem to work, they are probably canonicalized in all browsers. Maybe it was a developer choice to list Kolkata in Firefox and Calcutta in Chrome. FYI: Edge reports "Asia/Calcutta" too (not surprising, since it uses the V8 engine). Idem Safari. Anyway, read more in the Tc39 proposal-canonical-tz.

<script type="module">
import $D from "https://cdn.jsdelivr.net/gh/KooiInc/es-date-fiddler@latest/Bundle/index.esm.min.js";
const calcutta = $D({timeZone: `Asia/Calcutta`});
const kolkata = $D({timeZone: `Asia/Kolkata`});
console.log(`"Asia/Calcutta" time difference to your time zone: ${calcutta.timeDiffToHere}`);
console.log(`"Asia/Kolkata" time difference to your time zone: ${kolkata.timeDiffToHere}`);
</script>