It's 7 hours. If you take lunch it's 6!
6 hours
3pm to 10pm is 7 hours.
According to sources it is possible to go on lunch at 11am until 3pm. This is alongside counteless breaks.
13
3 hours between 12pm and 3pm
24 of course !
6 hours
2 hours
5 hours
9 hours
19 hours.