Is it possible to use tethered shooting with a Mac and a Powershot A4000 IS?

Does anybody know if it is possible to use tethered shooting with a Powershot A4000IS and a Mac? I'm guessing it's not but I'll ask here just in case. I would like to set up my camera to take pictures every 30 seconds for about 8 hours, but it looks like that functionality isn't built into the camera, nor does it seem possible to use a 3rd party capture program with the mac. I had an old Powershot that I used to be able to do this with (connect and shoot) but it looks like that functionality has been removed.

I took a look at CHDK but it seems that there isn't a port for A4000 (yet...).

Does anybody know of a way to do this or am I just out of luck.

I do have Windows on my Mac, so that is a possibility. Does anybody have any advice for the windows side of things?

Thanks