It’s probably nicer to schedule this with iCal instead of crontab. Create a new iCal event, and add an alert for that event that runs your script. You can easily and visually configure the event to repeat only on weekdays, and the best part is that you can simply delete or modify single instances of the recurring event to deal with exceptions like holidays.

Shameless plug. I always have trouble waking up. Since the Mac App Store came out this year, I've been working on a simple alarm clock app called "Mornings" to do just this (play iTunes or custom MP3s). It actually uses AppleScript to tell iTunes what to play for the iTunes option, so it works with whatever is in your playlists. (The "con" to this is that iTunes automatically opens when the alarm clock plays -- unlike other, more fancy apps, that load the playlists from iTunes but roll their own playback behavior.) Or you can just add your own MP3s and the app won't open iTunes.

I haven't posted it on HN before, but I'd be absolutely grateful if anyone tried it out. As a developer I get some promo codes, so here are some codes (hit Featured, then Redeem to grab it. Or if none of them work, e-mail me and I'd be happy to give you one.)

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AppleScript does not take into account the system volume level or mute status. That should be the first line of the script.

I've been using "sleep 28000; mplayer whatever.ogg" as an alarm clock (without any special app) for a few months now. Less polished, but it works. :-)

Back in the days of Mac OS 9 (IIRC), it was possible to schedule the boot time of Macs, and have a script automatically play the CD present in the drive.

I don't remember the very details because I only used the (second hand) Mac for a few weeks, and the scheduler wasn't reliable (anymore?). But still, it was a cool trick.

come on, just 'man at' and use vlc and point to a mp3. been doing it since 2001.

This one works well for me, and it's free: http://www.robbiehanson.com/alarmclock/

The last version was released in 2007 but it still works great on Snow Leopard. I'm in no rush to replace working apps with Mac Store apps.

I've got an old laptop running BSD, and for those days that I absolutely need to be awake at a certain time I tend to schedule, using at, for a cat /dev/random > /dev/snd. Never fails to wake me up :P

I would like this solution better if I knew a way to play an audio file from "the commandline" without having to rely on a big app like iTunes or VLC.

That's cool, but doesn't everyone use their cell phone as their alarm clock?