Windows and Mac: Citrus Alarm Clock is a free alarm clock that you
can customize not only for different days of the week (and different
times), but with your very own audio files.
For example, this week I've got to take the kiddos to about five
different places. I set up alarms for said events, with different audio
files for each one (Ladysmith Black Mambazo for camp, Mindy Smith for
soccer, Rolling Stones for the dentist, etc.). Citrus Alarm Clock is a
free download, both Windows and Mac systems are welcome.