One of the things I admire about my fellow health care practitioners is their ability to adapt (and function) with new schedules. Most folks go through life working their normal 9 to 5 lives of quiet desperation. Weekends are weekends for these people. Bedtime is always the same. Make one little change outside of the urbanus rattus schedule and chaos ensues: most don't deviate at all. I remember when we had to stay up all night with my Mom who was in the hospital, nobody could take the night shift. I had to do it. Staying awake all night was just too painful for my siblings.
As an RN, I've worked all the schedules. I've had the cushy 9 to 5 job working with the State of Nevada. I've done the 12 hour night thing (never again!). I've worked swing shifts. I've worked days. There isn't an hour of any day that I haven't been awake and working during it. I don't think many professions can say they've endured through that.
So now I'm in a new shock to the body. Working from 1pm to 9:30 pm. I've fallen into a pattern of taking some semblance of a walk in the morning. Or sometimes in the evening. My goal is to start jogging/running during the morning. Soon. Very soon.
But right now I just have to let this body get used to a new schedule. For me, I find that it takes about six months to make the adjustment.