overnight with dad...at what age?

snozberries

My ex boyfriend wants to take our 3 mos old daughter to stay the night with him once a week. I think he's out of his mind, we dont have any court order anything because we communicate well with each other and as of right now we havent had issues with him coming over to see her, but now he wants to take her, so my question is, Im in california (i know the laws are different in every state) at what age can he take her overnight?