Under a court order, my ex spouse has the kids for four weeks in the summer. Can I deny him those weeks because of a conflict?

Florida law is clear that time sharing with children is determined to be in their best interest. Consequently you cannot deny legally the contact for four weeks between children and a parent just because you’re having a fuss up with them. The only way that you can disobey a court order is to go to court and get another order saying that you have a right to deny that contact. If you fail to provide the contact, then you are at risk of being found in contempt, being compelled to give them makeup time for four weeks and being sanctioned for attorneys fees and even other sanctions added to that.