I am definitely a late riser (an owl). My day usually starts at nine o'clock, on weekends even later. In return, I'm super happy to work even around midnight.
Last week, however, I had an invitation to a lecture with colleagues from cardiac surgery that took place at 7:30. This was a (small) challenge. ;-)
But the lecture was a lot of fun and there was a lively discussion, which also led to new ideas for projects.
It seems, if you like to work in the clinic you should not be an owl.