How many hours can you work ?

That's the one thing I like about our call- it's broken down into 8 hour blocks. As for weekends, it's every fourth with usually a combination of three shifts of work and call (could be three shifts call; one shift work with 2 shifts call, etc.)

Wow, I didn't realize how lucky we are where I work. We're staffed 24/7, (for weekends/holidays- 3 on days, evenings, 2 on nights)
The only call we do is one person from day shift will take call for evening shift, and one person from evening shift will take call for nights. So if you would need to stay or get called back, it would be 16h working. But then some people do doubles when we're short and that's definitely 16h.