BTDT - when we moved overseas, we had to switch schools unexpectedly and the boys started 3+ wks late. I had more problems than I ever expected, and it wasn't with the ADHD/Aspergers 2nd grader, it was my uber-social K kid that had problems.
Unfortunately, in that 3+ wks, the boys had already started to bond and form groups, and my little social butterfly, type-A leader had a rough time fitting in. It was so bad that the K teacher repeatedly asked us to have him evaluated for anger management issues - issues which have never surfaced after that year. This should have been a non-issue for us. They were going to an American school with a turnover of 20-30% each year due to parent transfers in and out. they were used to dealing with kids showing up at all ages and stages and times of the year, with many speaking little or no English and reading/writing even less English. And they still were not able to help us with this transition. I do believe that if he had started the first day, some of these problems would have been avoided. Not all, after all we moved 4000 miles to a country where English was not the primary language and where they didn't get to see their grandparents, plus their mommy became a SAHM. It was stressful.
I'm certainly not saying that your child will have these problems. But you do need to consider his personality and the make-up of the new school. Even if you decide not to have him enrolled until Sep 1, ask if he can visit on the first day of school (if your official move date is not until Sep 1, he will not be counted absent the other days b/c he won't be officially enrolled, and I know from experience you have to have a utility bill or lease to enroll and it will not be official until Sep 1). Get him assigned to a classroom and give the teacher a picture of him. That can be a reminder to the other kids that their room is not complete. Be sure to have him meet the child who will be his "guide" (even if it's not school policy, the teacher will do it if you ask), and maybe he can even find that person on his own that first day.
Anyway, that is my dissenting opinion, based on experience. The move will be stressful for your son anyway; if you can do some things to make it easier on him, that will make it so much better. So, try to do some of the transition items I've mentioned above if you can't enroll prior to Sep 1, and be sensitive to your son during this exciting time.
The good news is that my kids really loved our experience with the move, and when we moved back to the US after 2 yrs, the transition was flawless. Granted, we moved during the summer, but taking care to consider their needs a little more that time made the transition easier (we brought them on our househunting trip [they stayed with relatives while we toured homes] and showed them the new house, let them pick their bedrooms, took them to their new school to meet the principal and see the facility, etc).
lmao
is to just wait until the 1st. As a mom I would do the same thing!
), the thing tht gets to me is this is Kindergarten. Certainly far from a big deal, but it will be the first time of getting used to "the big kid school". They'll start getting to know each other and the teacher will already have the ground rules established in two weeks. Even just half days, it will put him behind. 
