Can Luxon retrieve a list of all valid timezone names?

[Lx]

I'm trying to implement functionality in my app that allows the user to enter a local time, and then assign a custom timezone identifier for a different timezone (e.g. Asia/Ho_Chi_Minh).

I'm doing this so that due dates/times can be entered relative to a remote location without the user having to manually calculate what the local time of their current location would be at that instant (and maybe get it wrong due to DST changes, etc.).

Luxon lets me retrieve the timezone identifier for the current location:

DateTime.local().zoneName

but I'm having a hard time establishing whether or not Luxon will allow me to retrieve an entire list of all valid identifiers. There's no obvious API call in the docs for this, and I'm mindful that as Luxon calls on the browser, it most likely doesn't maintain its own list internally.

Is there a means of achieving this through Luxon? If not, are there any alternative recommendations for this need?

[icambron]

No, unfortunately, there's no way to do that until the Intl library is able to supply that. I've asked for it to be added, but as far as I know it's not even in the works.

[Lx]

Appreciate the confirmation. Do you have a recommended alternative for this in mind?

As far as I’m aware, Moment Timezone is the most accessible alternative that definitely offers this ability, but I’m certainly open to other libraries if you have suggestions.

[icambron]

@Lx yeah, Moment Timezone is probably your best bet.

[zdraganov]

I'm managed to get the list of supported timezones (and later cache it) using tzdata library and the following code snippet:

const {DateTime} = require('luxon')
const {zones} = require('tzdata')

const luxonValidTimezones = Object.entries(zones)
  .filter(([zoneName, v]) => Array.isArray(v))
  .map(([zoneName, v]) => zoneName)
  .filter(tz => DateTime.local().setZone(tz).isValid)

[vvo]

For anyone reaching this issue, I too needed to get a list of time zones. Even better I wanted to have a simplified list of time zones just like Google Calendar does. When grouping them is safe, let's group them (safe = same country, same DST rules). And I wanted this list of time zone to always be "up to date".

Since I could not find a good list that would also be maintained, I created an npm package for it: https://github.com/vvo/tzdb/. The list of time zones is automatically updated when there are changes (like new time zones).

You can then use luxon if you need to manipulate dates with time zones.

Good luck!

[brunolm]

Is there a way to get the abbreviation with the name?

e.g.

PST America/Los_Angeles

[vvo]

Is there a way to get the abbreviation with the name?

Yes, see https://moment.github.io/luxon/docs/manual/formatting#table-of-tokens. The formatting token is "ZZZZ" (abbreviated named offset), good luck!

[justingolden21]

Coming in from 2021 here to mention that getting a list of timezones would be useful, so we don't need to copy from an external source, that source then needs to be updated and in sync with luxon, or use another external library which also needs to be in sync with luxon. Luxon already has the information (clearly, since it uses it) so not only should be be easy to add, but much lwoer file size than adding redundant data. Just my 2 cents, love luxon : )

[brunolm]

I agree with @justingolden21 .

And to clarify how I solved the issue, well, I did exactly what Justin said, I have a redundant map that I have to sync.

[peetjvv]

I'm managed to get the list of supported timezones (and later cache it) using tzdata library and the following code snippet:

const {DateTime} = require('luxon')
const {zones} = require('tzdata')

const luxonValidTimezones = Object.entries(zones)
  .filter(([zoneName, v]) => Array.isArray(v))
  .map(([zoneName, v]) => zoneName)
  .filter(tz => DateTime.local().setZone(tz).isValid)

Note that .filter(([zoneName, v]) => Array.isArray(v)) seems to remove some legitimate timezones in Africa, e.g. Africa/Addis_Ababa.

I found this method more foolproof. Also, some of the timezone names from tzdata seems to be duplicated - hence the Set to remove the duplicates.
The sort is optional - all depends on whether you need them alphabetised for your use-case.

const {DateTime} = require('luxon')
const {zones} = require('tzdata')

const luxonValidTimezones = [
  ...new Set<string>(
    Object.keys(tzdata.zones).filter(
      tz => tz.includes('/') && DateTime.local().setZone(tz).isValid
    )
  ),
].sort((a, b) => (a < b ? -1 : 1));

[sfertman]

Is there a way to get the abbreviation with the name?

Yes, see https://moment.github.io/luxon/docs/manual/formatting#table-of-tokens. The formatting token is "ZZZZ" (abbreviated named offset), good luck!

Link changed to: https://moment.github.io/luxon/#/formatting?id=table-of-tokens