A non custodial parents
A non custodial parents has the “right” to parenting time with their children. If they exercise that right or not is their decision. It can not be forced upon them. They also have the obligation to pay child support.
Occasionally I can not get my kids on a weekend because of work and my ex gets mad as hell when I call her up and tell her. I guess it mess up her plans for the weekend, but she should have through about that before she fought me in court and refused to let me have joint custody.