One day is too far in advance to know your schedule.
Two of our teachers are ill, so some of us are doing extra hours to make sure that the students get what they pay for. I don't mind working overtime, because we're coming up on exam season and there are a lot of things I can do with the students to better prepare them.
Last Thursday, I took two of Nice Spanish Teacher's classes as requested by Bossman. Before I left that day, I asked BM if he knew if NST was coming in on Friday, or if he'd need me to take one of his classes. BM told me that he didn't know, so I asked the secretaries, who also didn't know. I asked Bossman if he'd call NST and find out, and was told that the secretaries were supposed to do that (and of course they claimed that they had, but still couldn't tell me). Frustrated, I left (it was 19h).
At 19h30, Nice French Teacher called me at home and told me that she had just talked to NST and he was coming in on Friday, so I didn't have to. Friday came, NST taught one class and went home again (we didn't see each other that day).
Later that day, BM asked me if I'd teach NST's classes the first two classes on Monday (today) if he didn't come in. I asked BM how we'd know that, and told him that I wouldn't be very happy if I came in and saw NST there also (especially on a Monday morning). We went through the same routine as Thursday. BM then looked at me and told me to call NST at home on Sunday and find out if he was or wasn't coming in today, and come in if he didn't. That was the final straw. I told him to forget it, I don't do scheduling, not to schedule me cover NST's classes on Monday and left.
It turns out that NST did come in today, but Ignorant Secretary tried calling me at 9h22 to see if I could teach Correspondence Teacher's class at 10h05, because she was ill. What a shame that I had turned my mobile phone off before I went to bed.