It takes approximately 6 hours for one day to pass in-game. Four of those hours are daylight, the other two are night.

Werewolves and Vampires spawn in Bangkorai at random times on random game nights. It was originally tied to the phase the moons were in, but that changed.

This makes it difficult to tell just when the infectious werebeasts and vampires will spawn. But it also means that it's less likely that lots of griefers will be able to camp spawn points and kill the monsters to keep others from getting infected.

As for the moons, wait until it's a clear night and look up at the sky. If you don't see anything, try moving to a different area without objects that will block your view of the horizon. You'll see them.