I would like to know what the workload and responsabilities of a Long Distance train crew is?

On a long distance train (such as the CZ) where it takes at least 50 to 60 hrs to go from CHI to EMY (or from EMY to CHI) what are the working hours of the crew? Do they have 3 shifts? (DAY, SWING, MIDNIGHTS).

Now I realize that 90% of the activities onboard a train occurs between the hours of 0600 and 2400HRS. What happens during the overnight hours (between 2400Hrs-0600Hrs.)

Although most of the passengers are settled down for the night by Midnight, I am sure that there are some passengers who are primairly night people who are up all night and sleep during the day.

If a passenger needs the services of an attendant at 3 AM, how readily available are they?

Since the CREW is responsible for the safety of both the passengers and the train itself at all times during the trip, do they have Crew members awake and on duty during the overnight quiet hours? (11 PM- 7AM)