Unexpected 24-hour time format in en-AU

In Australia (en-AU) a 24-hr time string to represent midnight is expected to be 00:00. However, 24:00 is returned.

For example the following returns ‘24:00’… DateTime.fromISO('00:00').toLocaleString({ ...DateTime.TIME_24_SIMPLE, locale: 'en-AU' });

whereas the following return ‘00:00’… DateTime.fromISO('00:00').toLocaleString({ ...DateTime.TIME_24_SIMPLE, locale: 'en-GB' });

As far as I’m aware Australia also commonly expresses midnight as 00:00 not 24:00.

[dlbass]

@icambron We have been ignoring complaints about this issue in our app for a while now, and just today decided to deal with it. After reading this thread, and then a bunch of fumbling through Unicode documentation we found this table (see Day Periods at the very bottom) showing that the ICU has the correct data. However, Chrome, Edge, and Android all display the incorrect 24:XX, while Firefox, Safari, and iOS display the expected 00:XX.

Your fix to add hourCycle: 'h23' solves the issue in Chrome and doesn’t appear to cause any issues with the browsers that already display the time correctly. That fix is also documented in the Google Chrome Help forum.

MDN describes the behavior we see in Chromium, but I don’t see the ICU data supporting Chromium’s choice to show h24 over h23.

We use Luxon a lot, and really hope to be able to leverage hourCycle to fix this time display. Regardless of what is correct for the locale, being able to show the time how we want would be very handy.

[icambron]

It’s something browser is doing. Luxon uses the Intl API, like in my first code snippet above. Then the browser uses its data, typically taken from ICU, to provide the strings.