I don't think you get a say in the scheduling as far as the arrival date. I never did, at any rate. My last two cats presented themselves and that was that. My first and third dogs, also (though Zeke was a stray for only a couple of hours, when he turned up I knew if I couldn't find the owners he would stay with me. Who knew that a year later he would come for a long visit and stay 12 years.)