Ability to remove periods and not display time

Hey Shawn,

I have been checking out your jquery-cron plugin to help with a new scheduling feature in an app I am working on.  We didn't want to allow users to enter a schedule that is more frequent then daily.  We also wanted to remove the time option, since this scheduled work can/will be heavy weight requests against our app.  Let me know if these commits will work or if I could tweak anything to help get it into the main repo.  This is my first time wokring on a jquery plugin, but hopefully the changes will work out.

Thanks,

Chris Lamb