I got my current part-time weekend job just after I lost my full time hours at work. When the Gods close a window, they open a door. I knew that my job was to "temporary" until the person I replaced could come back to work. I never expected almost 18 months later, to still have this insane schedule, but I do. My weekend boss and I get along and like I keep telling him, if it works for you, it works for me.
My co-worker is out again this winter for extensive surgery and unable to do her work. Good for me, not good for her. She is supposed to be out of commission until at least May, if not later. Not wanting a repeat of last year where I was given like no notice that my co-worker was coming back, I've started to ask my weekend boss if he has spoken to said co-worker. He probably was in contact with her last year and did not want me to know when she was coming back. Even though I knew my job was "at will", I was still caught a bit flat footed, especially when I asked for some notice, which I thought was only fair.
I will keep asking him until I get an answer. He has asked if I still want to work at the facility, which I do want to do. As I've told him before, I really just need to know what the schedule is so I can make plans to cover my needs. So lets see what he comes up with.