1998020 - Temporal: ZonedDateTime with out-of-range date should be rejected

Status: NEW

(Core :: JavaScript: Standard Library, defect, P3)

Description

[Tim Chevalier]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:141.0) Gecko/20100101 Firefox/141.0

Steps to reproduce:

js> Temporal.ZonedDateTime.from('-271821-04-19T11:26:00-12:34[-12:34]').toString()

Actual results:

"-271821-04-19T11:26:00-12:34[-12:34]"

Expected results:

A RangeError should be thrown, according to the spec, which uses CheckISODaysRange: https://tc39.es/proposal-temporal/#sec-temporal-interpretisodatetimeoffset (step 7)

SpiderMonkey's implementation of InterpretISODateTimeOffset calls ISODateTimeWithinLimits instead:

https://searchfox.org/firefox-main/source/js/src/builtin/temporal/ZonedDateTime.cpp#97

but this allows for a date string of -271821-04-19, which is inconsistent with the behavior of CheckISODaysRange.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::JavaScript: Standard Library' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[André Bargull [:anba]]

I consider this a spec bug -> https://github.com/tc39/proposal-temporal/pull/3014.

For example this works in SpiderMonkey:

js> Temporal.ZonedDateTime.from('-271821-04-19T23:00[Etc/GMT+5]').toString()
"-271821-04-19T23:00:00-05:00[Etc/GMT+5]"
js> Temporal.ZonedDateTime.from('-271821-04-19T23:00[Etc/GMT+5]').offset    
"-05:00"
js> Temporal.ZonedDateTime.from('-271821-04-19T23:00-05[-05]').toString()
"-271821-04-19T23:00:00-05:00[-05:00]"
js> Temporal.ZonedDateTime.from('-271821-04-19T23:00-05[-05]').offset
"-05:00"

But when using the spec polyfill:

>> Temporal.ZonedDateTime.from('-271821-04-19T23:00[Etc/GMT+5]').toString()
"-271821-04-19T23:00:00-05:00[Etc/GMT+5]"
>> Temporal.ZonedDateTime.from('-271821-04-19T23:00[Etc/GMT+5]').offset
"-05:00" 
>> Temporal.ZonedDateTime.from('-271821-04-19T23:00-05[-05]').toString()
Uncaught RangeError: date/time value is outside the supported range

It doesn't make much sense to me that a time zone offset of -05 is supported when using named time zone, but not when using time zone offset strings.

---

And it even more confusingly, the spec doesn't apply the same restrictions for the maximum allowed date-time value. This works in both SpiderMonkey and the spec polyfill:

js> Temporal.ZonedDateTime.from('[phone]T01:00[Etc/GMT-9]').toString()
"[phone]T01:00:00+09:00[Etc/GMT-9]"
js> Temporal.ZonedDateTime.from('[phone]T01:00[Etc/GMT-9]').offset
"+09:00"
js> Temporal.ZonedDateTime.from('[phone]T01:00+09[+09]').toString()
"[phone]T01:00:00+09:00[+09:00]"
js> Temporal.ZonedDateTime.from('[phone]T01:00+09[+09]').offset
"+09:00"

Comment 3

[Philip Chimento [:ptomato]]

My conclusion is that this is not a spec bug — see discussion starting at https://github.com/tc39/proposal-temporal/pull/3014#issuecomment-3784381106 and particularly https://github.com/tc39/proposal-temporal/pull/3014#issuecomment-3856086253