Not 100% sure this will be helpful, but I have called baggage services anywhere between 5:30 a.m. -9 p.m. I would not be concerned about calling too early, but I do think there is an hour at which they close.
At the values (don't know about elsewhere) you call for the luggage service and you need to be ready when you call and wait in the room with the bags until they arrive. usually it is around 15 minutes, but be aware that they do NOT give you a time, just "shortly" or "next." so I would not call if in a hurry.