Getting back on topic, I think one of my co-workers is heading for a bit of Professional Darwinism!
She works as a waitress Thursday lunchtime, and Friday/Saturday/Sunday evenings. The evenings don't seem to be a problem for her, but every single Thursday for the past month, she's had some excuse why she couldn't come in. Car trouble, a sick dog, the flu, and a burst pipe in her house. Strangely, none of these things have been an issue the following evening.
She hasn't been reprimanded really yet, because the boss is a bit of a softie and he likes her, but I can't see it going on much longer without something happening.
However, on a lighter note, it has led to a lot of us musing on what she's doing with those extra four hours!