How to specify a TimeZone when creating a DateTime object in Dart/Flutter?

Question

Dart?flutter does not appear to allow a timezone (eg: \"Australia/Sydney\" or \"America/Detroit\") to be specified when creating a DateTime object. Either the local timezone

Answer 1

You have to do a bit of magic to get package:timezone to work in flutter.

Extract whichever data file you need (there are 3: default, all and 2010-2020) and move it to your flutter assets folder. (I use 2018c_2010-2020.tzf, which is available in a branch.)

Add it as an asset in pubspec.yaml:

  assets:
    - assets/2018c_2010-2020.tzf

Then load that file on startup (e.g. from the initState of a top level StatefulWidget) and use it to initialise the database.

ByteData tzf = await rootBundle.load('assets/2018c_2010-2020.tzf');
initializeDatabase(tzf.buffer.asUint8List());
...
Location newYork = getLocation('US/Eastern');

I haven't tried, but you may even be able to load it from main if you mark it async.

I also notice that I must have cloned the latest branch, as I see this in my pubspec

  timezone:
    path: ../../dart/source/timezone

... but looks like you just need to grab 0.5.0-dev-2 from pub

dependencies:
  timezone: "^0.5.0-dev-2"