Date.prototype.toLocaleFormat is a non-standard API and we plan to warn when it's used (bug 1299900) and eventually want to remove it completely (bug 818634). As a first step we need to replace all Date.prototype.toLocaleFormat uses in Firefox with standardized APIs. toolkit/content/widgets/datetimepicker.xml uses toLocaleFormat with the following format strings: - %X and %x: These formats match (more or less) Date.prototype.toLocale{Time,Date}String, so they were updated accordingly. I've added "-u-ca-gregory-nu-latn" to the default locale to ensure the formatted strings use the Gregorian calendar with Latin numbers. - %B and %a: When the Intl object is available, we can simply use the additional parameters for Date.prototype.toLocaleString to retrieve the month/week name. But when Intl isn't available (bug 1215247), JavaScript doesn't provide any standard method to get the localized month/week name. So for the time being, toLocaleFormat still needs to be used until bug 1215247 is fixed. Nevertheless let's try to switch to the standardized APIs for those platforms which provide Intl support.

Comment on attachment 8805724 [details] [diff] [review] toolkit_content_widgets.patch This code shouldn't run on Android, so Intl should always be available.

That's great news, so we don't even need the toLocaleFormat() fallback for Android! I've updated the patch accordingly. Carrying r+.

Thanks for reviewing the patch!

Pushed by cbook@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/88013961312c Remove Date.prototype.toLocaleFormat uses in toolkit/content/widgets. r=Neil