How to convert a time to the current timezone

[bsutton]

I have a datetime in gmt and need to print it out in the local timezone.

I thought I could do something like:

var gmtTime = DateTime.parse('2020-10-27 06:10:05+00:00');
var offset = DateTime.now().timeZoneOffset; /// this is a duration
dateTimeToOffset(datetime: expiryDate, offset: offset) // this is a double?

I'm really not a big fan of using doubles as the lack a unit.
Dart has really formalised Duration so I would expect this type of library to also use it.
The above impedance mismatch also causes problems.

The doco also doesn't state what unit the double is in. I'm guessing its hours?

I end up with:

var gmtTime = DateTime.parse('2020-10-27 06:10:05+00:00');
var offset = DateTime.now().timeZoneOffset; /// this is a duration
var hours = offset.inHours + offset.inMinutes / 60;
dateTimeToOffset(datetime: expiryDate, offset: hours) // this is a double?

But given the library is meant to make things easier ;<

[bsutton]

I also don't think this is working as the date appears to be wrong.
My timzone is gmt+10 so I would expect the resulting time to be 4:10pm.
Instead I'm getting:
2030-10-28 02:10:05.000Z

[AKushWarrior]

Again, this is really late. Apologies.

Using Duration is a good idea, but this library has a sizable user base, so I'm wary of making any significant breaking changes. The double should be in hours, yeah. I think the issue is that, when you use DateTime.parse(), it interprets it as being in your current time zone.

I don't know why that error occurs. The time occurs to have "double-dipped" - it's 20 hours ahead of UTC instead of 10. I'll investigate and maybe publish a fix.