My hams change from month to month! They tend to get up about 15 minutes to 1/2 hour earlier each few days. Before I know it, they are day hammies!!! Then they keep doing it until they are night hammies. Right now Almond is an evening hammy and Nutmeg is getting up around 1am.
What you can try to do is to start "accidently" bumping the cage a little earlier each day until hammy gets up at a better hour for you. It does work sometimes.