As you probably already know, Hamsters are nocturnal animals, and sleep during the day, and are awake most of the night. Your Hamster, if it is young, will sleep a lot, and as it gets older, eventually will start waking up and being more active at night. If you are very concenerned, I would suggest a trip to your Vet, to be fully sure. But I honestly think there is nothing to worry about. You can also teach your Hamster to live on your regular schedule, so it has a pattern much like your's, all except the fact of it still sleeping during the day, because that is normal. Wake it up if it is still sleeping sometime in the night. If you have an exercise ball, put it in that for a little run around.
Do not worry about your Hamster, but, as I suggested, if you still are, ask a Vet.
ta ta!
Teenier18