[bwooce]

Well, no there are several good cases where storing a time in UTC as seconds since an epoch is wrong.

It's a common mistake.

The first usecase is Birthdays. For most purposes people do not want to store the extract time and date of their birthday in the original time zone. Apple do this, much to my annoyance - it means people's birthdays change as you move around our planet, and that doesn't align with how they work in the real world. If I'm born in Utah on 1/1/1980 it does not mean I celebrate my birthday on 31/12 when I'm in Australia.

The second usecase is recurring meetings, particularly with global participants. The mind bending case is where you have DST in some or all of the TZs. The only remotely correct thing you can do is keep the meeting at the same wall-clock time in the TZ of the meeting owner (9am meeting stays at 9am). Most apps don't, and there is no perfect answer (consider a participant in a different TZ - the meeting changes to a possibly conflicting time).

Sometimes storing the absolute time/date is correct. Other times storing the original UTC offset, as well as the time in UTC is. But most of the time, yes, store it in UTC in whatever form you prefer.