Shings -Indeed you are right on general times/hours. Halfords have early/late shifts of 9-5.30 and 11.30-8 and you have to work one weekend on, one off with a day off during the week, every week. As you noted, this works perfectly fine and always has done, but changes are to be made.
I am hoping the manager can work out a few things for at least a few of us. And yes opting out sundays has been unoffically frowned upon to the point where the rumour is you can forget progression/a career if you do so.