Why? Whoever wrote the schedule didn’t check, or someone added hours and didn’t check, or the schedule was entered into the system wrong, or someone forgot your availability, or at this time of year you are not available Thursday or Friday and someone scheduled you for Thanksgiving or Black Friday because “everyone has to work those days”. So many things can go wrong it’s unreal. The schedule that your leader made and the schedule that is published can be two different things.🙄