30 сент. 2020, 13:5530.09.20
There are 2 day changes:
- Daily quests reset at 0:00 UTC (there is a countdown on the page)
- Clan boss resets at 10:00 UTC
I don't know a place where week change is important. "Weekly" quests don't reset until you complete them, afaik.
Where it matters, there is a countdown. In arena, in tournaments, etc.
"Monthly" quests don't reset either.
Blue shard limit on the market resets on the first day of every month, never checked if it's 0 UTC or not.