In my area your start times for the next week must be posted by Friday. Meaning if you are forced Monday, it would have to have been posted Friday as a 6th day. They would have had to go in seniority order and offer the "extra work" to all Tue-Sat drivers in seniority order first, then force from the bottom. Lazy managers never do this so higher ups can file for money and not even work. If they had any brain they would have forced everybody and posted it Friday. There is no discipline for missing a day you never knew you had to work by the Friday before. They can threaten discipline but in the end there won't be any. Stay home, rest up. Life sucks bad enough already for anyone that worked Friday and worse if you had to work Sat. It's not like it snowed 2 feet anywhere.