Some Luxon zone offsets seem to be incorrect

[alberthtan]

Hey! When I'm using Luxon timezones, some zone offsets seem to be incorrect. Ex. Singapore returns +7:30, even though it is UTC + 8:00 (last time it was +7:30 was in 1981). Other examples include:

Turkey - returns +2 but is actually +3
Pacific/Norfolk - displays +11:30 but is +11
Pacific/Kiritimati - displays -10:40 but is +14

Is there any fix / support for this?

[diesieben07]

Luxon gets its time zone (and other locale) data from the underlying platform via the Intl.DateTimeFormat API. Do you have more information about the environment you are using, i.e. which browser/operating system/etc.?

[alberthtan]

I'm using Chrome and MacOS. For example, when I do this:

luxonDateObject.setZone("Singapore")

console.log(luxonDateObject.zone.formatOffset(
  now.millisecond,
  "short"
});

// returns +7:30 even though the correct one is +8:00
singapore time zone

[diesieben07]

now.millisecond is a value between 0 and 999 denoting the fractional milliseconds of the DateTime. Zone#formatOffset expects a unix timestamp in milliseconds. Therefor your code will always format the offset on some fractional offset within the first second of 1970/01/01. At this point Asia/Singapore was at offset +7:30, the zone was only shifted to +8:00 in 1982.
If you pass the correct timestamp to formatOffset you will receive the correct offset.

Edit: to get the unix timestamp in millseconds from a DateTime use DateTime#valueOf or DateTime#toMillis.

Edit again: I jused noticed that in your code you are using luxonDateObject.setZone("Singapore") without using the return value. Luxon's objects are immutable, therefor this call as shown has no effect.

[alberthtan]

Thanks so much! I'll try to figure out a solution.

Yes, I sort of abbreviated it for the context of the question, but I was doing something like "now = luxonDateObject.setZone..."

[alberthtan]

Thanks. Just resolved the issue with DateTime#toMillis!