Mine is 10 minutes and if I'm in a really great mood, I'll stretch it to 15.
That is assuming nobody called to advise of the delay.
Recently, I had one show up 25 minutes after the appointment time - that's definitely way over for me and I sent her beck.
I find it interesting that with some agencies, the escort knocks on the door right to the second of the appointed time each and every time I book with them and girls from other agencies are always late. I can see possible scheduling problems later in the evening after a girl has gone to a number of calls, but even then, it wouldn't kill the agency to pick up the phone and call or text.
What's your tolerance level in that regard?
And your experience?