I'm willing to help you (as a matter of fact, I already have a solution for you). However, I want you to show me what have you done so far. I'd like to know what are the problems that you're having.

There's a problem with your vendor_sched definition because you're using varchar instead of datetime columns.

The problem you're posting now is a bit different from the original as you don't need only the free spaces, you also need the booked spaces. As a hint, I can tell you that you need more rows and less columns.