As with all staff you have contracted weekly hours (39? I think) and onboard your line manager is expected to manage you within those hours. Apprentices have slightly different contracts and I'm sure one of them will give you the up-to-date information or trawl some of the other apprentice threads for that specific info.
Working hours is a bone of contention in the Chef cadre at the moment as there is a set of hours as you allude to, there is union meetings and all sorts going on to try and resolve this.
Generally start at 6ish, knock off around 12.30 until 3.30pm. Final service is at 6.15 so finish around 7 once Galley is cleaned. There is limited staff, however, Chief Cook will try to stagger starts and finishes as much as possible to keep working hours in check. Weekends at sea, same as weekdays. Weekend in port generally it is permitted to have a buffet dinner so only one chef on duty to put that out. Work hours is flexible. Unlike hotels/restaurants that work a fixed service, operational requirements can mean staff working late into the evening/night or early starts so early breakfasts and late dinners can happen.
Be assured that we are a militant bunch at the best of times and love to bitch about how easy every other department gets it - no-one wants to be flogged at work! Efforts are always made to make things as bearable as possible. It sounds a lot more terrible that it is tbh. I always think when you are at sea its all moot, working or not, you are still not with your family!
Time off: As an apprentice you will likely share a cabin - although they are reasonably sized it's no picnic, but you should have a TV. There are TVs in the bar also. Most people watch films and box sets on their laptops or bring games consoles. There is usually a small contingent who decorate the bar of an evening. When in port you can wander ashore on your time off. Most never make it past the first pub...
