36 hours if you come at 6am and leave at 6pm the following day.

But now life v good. They go post call at 12pm next day. So just 30hours

But then they also dont really come at 6am. More of come at 7am so 29hours.

Usually they will have at least 3-4 meal breaks of half to 1 hour each. So become 26hours.

Plus they talk cock sing song in MO room so minus 2-3 hours, so 23 hours.

Then on call, they go back call room to catch forty winks, so minus another 2-3hours, so 20hours.

So the 30+ hours is overestimate. My own experience is about 20 working hours per call.
Granted you are physically in hosp for that 30hours but you are only working or about 20 or less.