I sent him this on April 6th:
Due to summer time schedules filling up fast and getting daycare coverage, I have previously asked for your schedule of when you wish to have the children this summer. Therefore, beginning April 20th, I will go ahead and schedule (and therefore pay the necessary fees, etc) for them and you'll have to work around their schedule. Since out of the almost three months of summer you'll have them for two, two week visits, your desired dates may not be a problem. If they interfere, I'll let you know and you can make changes.
This is the last time I'll bring up the subject as you now have been notified.
He then proceeded to tell me to tentatively plan on the specific dates in August that I told him back in January that the kids won't be available. I sent an e-mail back telling him that that won't work and then gave him the almost three months of dates that would work. Like usual, he hasn't gotten back to me. So I STILL don't know when he's taking the kids!
I'm just afraid of going on with our lives and scheduling/booking stuff and then having to not do it because I legally have to let him have the kids for a month in the summer.
I wonder if I can get our papers modified to incorporate a cut-off date?