Yes, September would be nice but I can't get away then. I will need an extra week of leave, which the board would be unlikely to approve at that time of year as I mostly teach seniors and they'd be coming up to their finals.
Our school holidays (other than summer) are only two weeks, and two weeks for Europe isn't quite long enough for me - I need to allow a couple of quiet days at either end for jet-lag. I know some people who can push right through it but when I try to I get migraines.
So with travel time as well, that's basically a week shot just getting there and back.
Actually it just occurred to me that DH might sometimes have trouble getting leave in July because of end of financial year stuff, so it looks like it'll probably have to be April anyway. It's a shame Europe isn't nicer in January!