As a CT surgery resident, can confirm that I work 79.99 hours every week. No more. No less.
Seriously though my days are pretty variable.
If not on call, I get there around 5am to see patients and take care of floor issues, then I go to the OR. The length of my day is dictated by the OR schedule. If it's a light day, I can be done by 3-4pm, in which case I'll stay until 6 or so working on research, following up patient care issues, getting them tucked away, etc. If it's a heavy day, I can be there as late as midnight (and no I don't get to sleep in the next day). Most days are somewhere in between, so I typically leave around 7-8ish on non call days.
Call days are the same as non-call days except I'm in house overnight and my official call duties begin at 7pm when the CVICU attending and NPs leave for the day. I sign out the call pager to the next person around 7am. If it was a relatively easy call and I got a couple hours of sleep, I'll usually stay for a case in the morning and leave around 12-1p. If call was busy and I'm exhausted, I'll just finish seeing my patients that morning and leave earlier - around 9-10.
I work every other weekend (i.e.: work 12 days straight, get 2 days off). I much prefer this to a random day off during the week or just one weekend day as it lets me do real human activities on my weekends off...