ECMA-402 should allow numeric-offset host time zones

[gibson042]

Among other things, this would remove the need for ECMA-402 Temporal to override ECMA-262 DefaultTimeZone.

[ptomato]

Should this be a discussion over at tc39/ecma402 instead?

[gibson042]

I'm considering it a change that would be part of Temporal, but if it makes more sense to discuss there then that's fine.

[ptomato]

I think all the necessary changes on the Temporal side are in tc39/proposal-temporal#2171.

In ECMA-402 they would then delete their override of DefaultTimeZone and ensure that all of its callers are prepared to deal with a numeric-offset time zone. I think that further discussion should be had over there, because it doesn't affect Temporal.

[gibson042]

Affirmed by tc39/ecma262#2781 : tc39/ecma262#2781 (comment)

[sffc]

For example:

new Intl.DateTimeFormat("en", { timeZone: "+01:00" })

[sffc]

TG2 discussion: https://github.com/tc39/ecma402/blob/master/meetings/notes-2022-12-08.md#ecma-402-should-allow-numeric-offset-host-time-zones-683

Conclusion: Yes, move forward with a PR for this. @gibson042 kindly volunteered to make the PR.

[justingrant]

TG2 discussion: https://github.com/tc39/ecma402/blob/master/meetings/notes-2022-12-08.md#ecma-402-should-allow-numeric-offset-host-time-zones-683

Conclusion: Yes, move forward with a PR for this. @gibson042 kindly volunteered to make the PR.

@gibson042 - Is there a PR? Asking because a PR to resolve #741 may end up touching the same parts of the spec, so we should coordinate.

[ptomato]

Note, completing this issue should also remove the "If IsTimeZoneOffsetString(timeZone) is true, throw a RangeError exception." step from Temporal.ZonedDateTime.prototype.toLocaleString.

[justingrant]

Note, completing this issue should also remove the "If IsTimeZoneOffsetString(timeZone) is true, throw a RangeError exception." step from Temporal.ZonedDateTime.prototype.toLocaleString.

It's possible that future PRs (I'm working on one now!) may introduce other blocks of offset strings, so doing a full search for If IsTimeZoneOffsetString in intl.html in the Temporal spec is probably a good idea.

[justingrant]

@gibson042 - are you still on track to have a PR for this issue available for this week's TG2 meeting?

[gibson042]

pull request: #788

[FrankYFTang]

I need to investigate the cost to make the dft.resolvedOptions().timeZone return "+01:00"