I have a 3.5 day a week job they know I was hoping for another half a day so offered me Monday and Wednesday half day mornings as extra. They dropped the Monday half day which worked for me as I was struggling with the extra hours but now on the Wednesday I’m constantly doing extra and going well beyond my half a day should finish at roughly 12.30 but it’s going on well untill 4 o’clock some days as they need me. I need to say something and set an end time to my day as I’m having to cancel afternoon plans I was supposed to pick up some important bits from town and collect a form from my gp. I have a very lovely job and don’t want to let them down how would you word it are they allowed to have me work with no end time stated