Alarm Clock S.E. for Mac

From Humongous Elephants and Tigers:

Alarm Clock S.E. is the ultimate alarm clock for OS X. With its complex alarm system, you will be able to create alarms that fit even the most complicated schedules. Wake up to songs, run shell and applescripts whenever you want, and never miss an appointment again.
Three Alarm kinds:

• Specific date(s)
• Set of dates (i.e: all dates that have month of August and October, day of week of Sunday, and time of midnight)
• Periodic dates
• supported file formats include: aiff, .wav, .midi, .mpeg, .mp3 .mov, .dv, .avi, .swf
• play a set song, song(s) from folder, or a song off a webpage
• set expiration dates: never annoy your neighbors when you leave for the weekend again
• customize the speed and sound level that your alarm songs play at
• Like cron, run any command line arguments when an alarm fires
• Know applescript? Do everything you already do in applescript automatically
• Ready made scripts available so you don't need to know about Unix to do simple operations