The Regime says what will be expected of the prisoners per hour. You need a Warden to prepare the report.
There are 7 different types of Regime slots. However, it is possible to successfully run a prison without using all of them.
Prisoners will be locked up in their cells, which they are not allowed to leave. If they are locked up between 10pm to 8am they may choose to sleep, otherwise they will wander in the cell and use whatever happens to be available to meet other needs (toilet, shower, entertainment, etc.). If none of this applies the inmates will limit themselves to standing around in their cell, supposedly thinking about their mistakes, their families, the lives they'll have after prison and the blueprint of the prison's utility room they somehow got their hands on to, but keep in mind that prisoners have been observed being idle even if they have needs and the items to satisfy them in their cell.
Prisoners will be locked up in their cells and are required to sleep. Some prisoners, however, might refuse sleep, and sleep instead during the Free Time. If a Prisoner has smuggled a digging tool into their cell and has a high enough Freedom need, they will start digging a tunnel from his toilet when they're supposed to sleep. Sleep will only function correctly from 10pm to 8am. (You can schedule other things during those hours which would prevent sleep, but trying to get sleep to function outside of those hours will not work)
As of Update 7, Prisoners are now able to sleep during the daytime, allowing nocturnal regime schedules.
Prisoners will start eating only during this time. Prisoners will go to their cell block's assigned Canteen and grab a tray of whatever food you had prepared or them from the Serving Table. Once finished, they will use whatever facilities are available to them in the Canteen to satisfy their other needs. Cooks and prisoners assigned to work in the Kitchen will start preparing the food 4 hours earlier. You need to be careful when changing the time of the Eat Regime, because if you were to set Eat right before the current time, your Cooks wouldn't have enough time to prepare the food, which may under some circumstances lead to a Riot if Prisoners are desperate for food. (Also note that if you place free time after eat on the schedule then prisoners who arrived late to eat will finish eating during free time instead of going hungry; but they will not begin the eating process in free time, it has to start during eat time)
Prisoners will go to a Shower room and use any facilities available in the shower room to satisfy their needs. If you have toilets in your shower area, Prisoners will use them if needed during shower time. While it's not strictly required, most players choose to implement an hour of shower to ensure that everybody is squeaky clean and in new clothes.
As of Alpha 11, if a prisoner showers during Free Time, they will also change into clean clothes. Thus it is possible to have no shower time in your regime, replacing it with free time. However, the forced shower time can help control prisoner flow instead of letting them choose where they want to be at that hour.
If there are no accessible shower rooms for certain prisoners, they will simply go to their cell as if it's Lockup.
Prisoners will go to a Yard and use any facilities available to them in said yard.
Prisoners will go to the yard to exercise or use objects if they need to during Free Time as well. However, during Yard time, every prisoner will go to the yard, even if they would be better off going to other locations to satisfy their needs. However you can add outdoor showers and toilets marked as part of the yard so prisoners can use them on yard time (for hygiene needs) along with weight benches and seating areas. (to fill exercise and comfort needs)
If there are no accessible Yards for certain prisoners, they will simply go to their cell as if it's Lockup.
During Free Time, prisoners will do all activities except for beginning eating, working a job, or going to any reform programs besides Parole Hearing. Free time is a catch all to let prisoners meet whatever their highest need currently is and in a tight regime may be the only time a prisoner has to meet his entertainment needs.
There are two variants of Work time; Work/Lockup and Work/Free Time
During this time, prisoners may try to work at one of the available jobs in the prison or participate in a reform program. When all available job positions are taken, remaining prisoners will behave as during they would during Lockup or Free Time, depending on what is set. Work rooms (kitchen, laundry, etc.) must have prisoners assigned to them in Logistics or no prisoner will be able to work there. Careful planning of work hours can help reduce the number of cooks and janitors needed, for example: Preparing food in the kitchen takes 4 hours. The Work interval has to be set accordingly for food to be prepared by prisoners. The laundry and cleaning can be done almost entirely with prisoners, using janitors to focus on areas that are staff only or to finish off laundry that the prisoners don't complete in time. Work time is also used by prisoners for programs. Enough work time must be scheduled for each program you make available or prisoners will not be able to complete them.