web cam recording software via schedule

I have a 2011 mac book air with built in web cam. A bunch of included software from apple on it.

I want to be able to automatically turn on and record video from my web cam at a scheduled time ... for a certain length of time. Possibly use motion detection software but not primary requirement.

I don't mind possibly spending a little money for an application ... seems like there are so many out there but ratings on many are not so good.

What do people recommend?

Thanks in advance ... John