[Feature] Allow the default time to be configurable

[patrickkforrit]

This is a really small ask and completely understand if you decide not to do it.

When you open the timepicker the default value is the current time.

It would be nice to be able to default this to 00:00 or 12:00 for example.

There is a workaround for this right now to set the control to 00:00. But the value would be set at that point and we wouldn't be able to differentiate between a null value and a legitimate 00:00 selection.