I doubt that it is simply the matter of the duration but it looks more like the matter of time zones.  I imagine that for some people in Japan, 1:00am–2:35am is easier to compete than 1:00am–3:00am, although both would be difficult for me if I lived in Japan.

Oh, I think codeforces's coding time is too long (like ICPC) because codeforces's standing page is like ICPC's one.
Thanks for your comment! I will participate in today's Beta Round.