I had this exact problem a number of years ago and I open at 6am! He did tell me that he'd have to start dropping them at 5:45 to which I say, "um, no, I'm sorry, I don't open till 6". He left it there then showed up at 5:55 the next day. I thought it was just a miscalculation of his drive time and not wanting to be nitpicky, I let it slide. That lasted 2 days, then he started showing up at 5:50, then the next day at 5:45. Nope. I left the lights off and just didn't open the door till 6. So far as I know, he just sat in the truck with his kids for the remaining time. He asked if we'd not heard him and I indicated that I was in the shower getting ready as I don't open till 6. It didn't happen again.

Do NOT give in on this. It seems like a little thing, but giving in sets a precedent and some people will totally take advantage of it. JMO.