I am working to change my sleeping patterns. I have been a bit off since I had all that time off. The best sleep of the night right now is around 7:00am, which is about the time I should get up every day. I am working my way backwards now. Winter is always tough because I love being snuggled under the warm blankets at that time of day.
I don't know if most people do this but once I change a sleep pattern - even by accident - for a couple of days, it takes some time to move out of it. If I wake up at 3:30am two nights in a row, it will last for two weeks. If I wake up late a couple of days, it keeps happening until I can back it up. Usually, it requires one night of just not getting enough sleep so that I will be tired enough to go to bed early and reset everything.