What happens if dates are not adhered to in custody order?

If this was a unilateral decision by one parent (i.e., without the consent/prior agreement of the other parent) to usurp the other parent's court ordered visitation/custodial time with the children, then the parent who has had their visitation time interferred with/denied in this fashion can file a Rule to Show Cause with the court to have the violating parent held in contempt of court.

I agree with Ms. Mandell's view of this issue. Unless one parent has sole decision-making power over an issue like this, then deciding to deny the other parent they could not have the kids when they were scheduled would be a violation of a court order. A Show Cause action could be brought against you where the other parent seeks to have you held in contempt of court if you do not have a good reason why you violated the order. Substituting your own judgment for that of the court is not going to be seen as a valid reason to make changes to the visitation arrangement. For a violation like this a judge could order additional visitation to the other parent to make up for the loss, or have you pay the other parent's attorney fees if he or she hires a lawyer. If issues like this continually arise and you are found to be in contempt on multiple occasions you could possibly face jail time.