When QDateTimeEdit is configured to use a format that includes time-zone information, it overrides the user-supplied time-zone in the input, converting the user-supplied input to the time-spec (or, post-QTBUG-80417, time-zone) the QDTE is configured to be using. The architecture of the widget, parsing the user-supplied data from within a const method, makes it impossible to avoid this. We should find some way to change the widget's architecture to actually allow it to adapt its time-zone to the one the user is trying to supply.