Our school policy is for a teacher to call back within 24 hours.
If you called me this morning (I teach 5th grade), then you surely wouldn't have gotten a call back.

I had a total of 15 minutes to myself today, and it was spent on lunch (a very uncomfortable, swallow as fast as you can, can't even sit down, kind of lunch).
I came in to school at 7 am and left at 5 pm. My only planning period was taken up by a meeting with a principal, and right after the busses left at 3:20 we had a faculty meeting. I SWEAR I barely made it to the bathroom, and I actually took over 5 minutes of someone else's recess duty because that teacher needed to use the restroom as well.
I can't even begin to describe how little time there is during the day for a teacher to teach+plan+correct+make copies+meet with administration+meet with parents+return phone calls+complete building paperwork on inventory+contact math coordinator+call in about that field trip+...