I recently installed Android 13 via the October update. Among the changes is to set the first day of the week to Monday. Previously, on my device it was Sunday - my preferred option.
I know that I can specify the first day of week in the DatePicker class but I'd have to do that for every instance in every app (well over 30).
Q: Is there a way of setting that system wide? (Yes, I've looked!)
On Android 14 (not sure about older versions), there is a 'First day of week' setting under System -> Languages -> Regional preferences.