When you have to be out of town, or you booked another gig, say, for a sitcom, you need to do what's called "booking out" with your agencies. That way, they won't schedule an audition or a booking for that same day.
Since SAG has some weird policy where you can't even work on two union jobs on the same day (or is it week?), it doesn't make sense to keep yourself available on those days anyway.
As a freelancer and an occasional independent contractor, I have clients who want me in their office during a set schedule. I automatically book out during that schedule, unless it's an extended gig.
I just booked out for 4 weeks — 2 weeks in June, 2 weeks in July – because I have 2 very important clients I don't want to screw up with.
So here's why I'm writing today...
Today, my print agent just told me I've been put on avail for something I auditioned for about a month ago. A month ago! This business forces you to keep your memory short term. That way, you don't get all depressed from the dozens of jobs you don't get.
Most of my clients will understand if I can't make one day of their set schedule, and I'm hoping it won't be a problem if I should book this print job. They usually don't understand, however, if you need some time off just to go audition, no matter how "important" the job is to you. And, no, there ain't no fine line about it. It's pretty cut and dry here.
Oh, in case you're interested, it's for TIAA-CREF, which is a retirement fund that, I believe, was originally for teachers. It'll probably be used for web ads also.