The Arena/Co-op time you see in-game is not your local time but based on the server time.
Each server has its own server time, so finding the correct opening times for the arena may be challenging.
Opening times for Arena and Master Arena:
- Asia (Asia) server:
12:00 - 13:59 UTC+8
19:00 - 20:59 UTC+8 - North American (NA) server:
12:00 - 13:59 PST
19:00 - 20:59 PST - European (EU) server:
12:00 - 13:59 UTC
19:00 - 20:59 UTC - Latin American (LA) server:
12:00 - 13:59 BRT
19:00 - 20:59 BRT - Oceania (OC) server:
11:00 - 12:59 AEST
20:00 - 21:59 AEST
Opening times for Co-op:
- Asia (Asia) server:
15:00 - 22:59 UTC+8 - North American (NA) server:
15:00 - 22:59 PST / 16:00 - 23:59 PDT - European (EU) server:
15:00 - 22:59 UTC - Latin American (LA) server:
15:00 - 22:59 BRT - Oceania (OC) server:
15:00 - 22:59 UTC+10/AEST
After the update from April 6th, 2021, the Arena and Co-op modes will be available on a bi-weekly basis, which means players will be able to play one or the other depending on the week, instead of both being available at the same time.