What it does
Daybound is a transforming mechanic tied to the day/night cycle. A permanent with daybound enters as its front (day) face. If it's day and the active player casts no spells during their turn, it becomes night, flipping daybound permanents to their nightbound back faces. Once it's day or night, it stays that way until the opposite trigger occurs.
The big rules nuance: if there's no daybound or nightbound permanent on the battlefield, it's simply neither day nor night. The cycle only "starts" when one enters—and it begins as day. Also, a player casting two or more spells in a turn switches night back to day. The day/night state is a game-wide designation, not a per-permanent counter.
In Commander, day/night is shared across all players, so opponents' spellcasting affects your werewolves. With four players taking turns, it can be tricky to flip to night, since someone usually casts something each turn.













