Long and tiring
Unless you are full-time, you may be expected to work 3 hour shifts in the evening from 6-9pm. Management is very understanding when it comes to booking time off as long as you give them advanced notice. A typical full day shift is usually from 9:30 to 4:30pm or 1:15 to 9:15pm or 10:30 to 7:30pm. Employees who work full day shifts are entitled to a 1-hour break(unpaid) and 2 15-minute breaks(paid).
8 hours three times a week
Since my movie work was on call and almost exclusively weekdays, I would work weekends (anytime from opening to closing) and generally one to three days the rest of the week (usually opening - to receive stock but some closures as well), depending on the season
Short and decreasing with decreasing sales in most of the stores.