Yes a schedule is SO important! Your body gets used to the cycle and comes to expect it. It can really affect your health and how well your body can fight off infection. It's important for everything you do.
My schedule goes completely haywire sometimes when I'm up late working on the servers. Two night ago I went to bed at 8am. Last night I went to bed at 6am. I'm trying to work my way backwards to a more normal time
Maybe I'll go to bed at 4am tonight ...