This trick worked for some gacha games to reset stamina. It does nothing for Arcaea. The anti-cheat uses SHA-256 hash checks on the client version, not system time.
Go to Settings > Apps > Arcaea > Storage > Clear Cache . arcaea autoplay fix
: Features a toggle for AUTO PLAY (using the F4 key) that allows the music to play without player input, useful for enjoying the visuals and music without the stress of gameplay. This trick worked for some gacha games to reset stamina