[tz] Canonica and non-canonical timezone question

[Paul Eggert]

On 8/29/22 03:54, Andriy Hromyak via tz wrote:
> https://github.com/moment/moment-timezone/issues/828#issuecomment-1228548097
>
> could you please assist on providing info on how we can distinguish
> canonical and non-canonical timezones.

"Canonical timezones" is not a phrase we use, so I'm not sure what 
exactly is being asked for.

In general, if you stick with the timezone names listed in 
zone1970.tab's column 3 you should be OK:

https://github.com/eggert/tz/blob/main/zone1970.tab

For moment-timezone in particular, you can find currently-supported 
timezone names by looking at the source code for whatever version of 
moment-timezone you're relying on. Here's a reference to the current 
version with its full data:

https://momentjs.com/downloads/moment-timezone-with-data.js

As you probably know, moment-timezone is in legacy mode. If your app is 
still being developed I suggest switching to a replacement for 
moment.js, such as date-fns or dayjs. With a good replacement you should 
be able to simply ask your JavaScript platform by using 
Intl.supportedValuesOf('timeZone'), though you may need a polyfill for 
older browsers.

If you want a platform-independent list of names, zone1970.tab is 
probably your best bet.