setZone('America/New_York') producing 'Invalid DateTime' on ReactNative 0.59 (Android)

[bramski]

Version: 1.8.2
ReactNative: 0.59
Platform: Android

Trying to dig deeper...
The following code: DateTime.fromISO('2020-09-17T16:00:00-04:00') returns Invalid DateTime. Not sure if something changes in the javascript runtime or something...

[icambron]

That is pretty weird. Unfortunately I have no idea. Can you check invalidReason and invalidExplanation on that invalid instance?

[bramski]

I'm baffled as well... If I do the following:
import { parseISODate } from 'luxon/src/impl/regexParser';
and then parseISODate('2020-09-17T16:00:00-04:00') I get back the date parts.

[icambron]

Do you have any settings overrides, particularly defaultZone?

[bramski]

No settings overrides.
Dug a bit deeper this morning (we have a side library that takes dates and produces standard time strings for us from our API)
It seems that DateTime.fromISO is actually succeeding, but calling toFormat('h:mm a ZZZ') is causing the 'Invalid DateTime' to be returned.

[bramski]

Ah wait... it seems like there is an additional call in here that is failing:
setZone('America/New_York') is returning null and that is causing the toFormat to return an invalid datetime.

[bramski]

So it seems this isn't Luxon's issue, but Intl no longer accepts 'America/New_York' as a valid timezone on the latest upgrade of React-Native.

[bramski]

Solved by: andyearnshaw/Intl.js#19
You need the JSC intl support: https://github.com/react-native-community/jsc-android-buildscripts#international-variant
Also don't be a stupid and install the intl polyfill on react-native or you're in for a world of hurt (or your predecessor).
Fixes this.

[santiagofm]

Thank you @bramski for the thorough investigation! 🥇