Curse of the First Wolfmoon

Enchant Player
If it's neither day nor night, it becomes night
as Curse of the First Wolfmoon enters the
battlefield.
Creatures enchanted player controls are
Werewolves in addition to their other types.
While it's day, creatures that player controls
get -1/-0. While it's night, creatures that player
controls get +1/+0 and must attack if able.