Depends on your position and status as full time or part time.
Not very. I worked 4 10 hr shifts, Monday thru Thursday. HOwever the 10 hrs was usually a bit longer as I was considered management and I was a salaried employee (granted a generous salary). I was also on call about 1 weekend a month
Hours are very flexible to your own schedule. They work with you and availability. If your in school, have another job, or simply a preference of when and how long, they will work with you.
In Loss Prevention the working hours are very flexible. We made our own schedules.