Hi. I was a union employee for ~4 years and quit to go to school and came back this year for peak because it listed a $200 attendance bonus for showing up to work that week every day. However, the job was listed as monday-friday. I have been paid bonuses for working monday-friday for 3 weeks but now the supervisors are claiming anyone who doesn't show up Sunday is ineligible for the bonus despite no mention of it before anywhere on the hiring site or during the orientation. Can they arbitrarily change my hours like that for the bonus? The Sunday sort conflicts with my other job and is completely opposite hours of the night sort. Do I have any rights here, or is my only option to quit?