Creature — Phoenix
4 / 2
Flying
If it's neither day nor night, it becomes day as this creature enters.
Whenever day becomes night or night becomes day, you may pay


. If you do, return this card from your graveyard to the battlefield tapped.
Day and night are designations that the game itself can have. The game starts as neither. Once the game becomes day (or less commonly, night), the game will be exactly one of them—day or night—going back and forth for the rest of the game.