Formatting Dates in Flutter

I wanted to internationalize dates to French. Here's how I used the intl package.

All the information has already been documented in https://pub.dev/packages/intl, but I will summarize each element that I needed as well as some gotchas.

First I simply created my formatter like so: DateFormat.Hm("fr"). But this threw an exception because the date formatting locales haven't been loaded yet. You have to first call the asynchronous initializeDateFormatting(locale) which returns Future<void>.

Here's how to set it up properly:

import 'package:intl/date_symbol_data_local.dart';

const locale = "fr";

DateFormat timeFormat;

initializeDateFormatting(locale).then((_) {
  timeFormat = DateFormat.Hm(locale);
});

There are two important things to note:

• You want to import date_symbol_data_local, not date_symbol_data_local_file nor date_symbol_data_local_http.
• Simply initializing date formatting with a locale does not make it the default locale. You still have to specify the locale when instantiating a formatter.

Last useful tidbit, to make a formatter that combines date and time, you do it like so:

final dateTimeFormat = DateFormat.yMMMMEEEEd(locale).add_Hm();

And here's a properly formatted date time in French:

print(dateTimeFormat.format(DateTime(2019, 06, 06)));
==> 'jeudi 6 juin 2019 00:00'