Lloyd~ Early Bird, because he really wants the worm.

Kai~ Night Owl, he makes sure everyone is in bed at their bedtime. Nya especially. She breaks curfew all the time and he gets to ground her for it.

Cole~ Night Owl, he likes to sleep in even when he says he's not tired the night before. *This is me lol*

Jay~ Early Bird, similar to Lloyd, he wants the worm before Cole gets it. Zane only makes the food a couple minutes after Cole wakes up...

Zane~ Both! He's a nindroid, what do you expect. 

Nya~ Neither, she wakes up whenever she wants to and goes to bed whenever. She really doesn't care.