And you have to treat the timezone offset as information-free. As in, 02:00+00:00 and 04:00+02:00 are absolutely equivalent representations of the same data.

And you have to treat the timezone offset as information-free. As in, 02:00+00:00 and 04:00+02:00 are absolutely equivalent representations of the same data. If you need to know the timezone in which to display a time, you save that timezone separately