Can my employer force me to split my shift ?

I work retail and in years past since black Friday can be horrendous, they have asked if anyone would volunteer for a split shift or be able to stay more than 8 hours and some have complied with the requests. However, this year they are just forcing people to work split shifts and when I had asked if there was any way I didn't have to work a split shift they said we didn't have the coverage to have me work my regular 8 hour shift or work an extended shift that we would have people at the wrong times there rather than when they needed them. This year we do have a new manager so that is part of the reason because in years past they did ask and if you said no to either extending or splitting a shift then they didn't force you. I was just curious because I wasn't aware that you could be forced to split your shift because the business doesn't have the right amount of employees for substantial coverage those days. In our handbook there is nothing about working split shifts, so I was just curious because when asking my manager, she said we had to because we need coverage but I didn't know they can just do that to people when most of them are only working an extended or regular shift.