Can a part-timer be required to work six days? A midnight shift, normally Sun-Thurs, is suddenly requiring a Saturday sort and calling it "mandatory." There are dozens of guys that have second and third jobs already on the weekends. Both their second employer and UPS are threatening discipline or firing for not showing up. People build their entire lives and schedules around the workdays and hours for these jobs, and you can't just make a day up out of thin air to require. The jobs were compatible, and then UPS almost makes these guys choose which job they get to keep.