Ideally, your parenting plan gets put in a desk drawer and you never have to look at it because you both just do what’s best for you and your kids.
When that’s not working, follow the plan.
Sometimes we get calls from clients concerned about wanting to trade times with their co-parent, move things around, etc, and otherwise act not in accordance with the parenting plan. And that’s perfectly okay! As long as the other parent agrees, you can move your schedule around any way you feel would be in your family’s best interests. You will not be guilty of contempt of court for switching weekends if you both are cool with it.
We wouldn’t advise that you regularly miss your parenting time even if your co-parent agrees to keep the kids during that time, that can be grounds for modifying the parenting plan and permanently reducing your parenting time. But trading time, adjusting pick up and drop-offs, rearranging holidays, that is all fine.
When things are not good between you and your co-parent, the default is always whatever the parenting plan says. If you’ve been following a regular day-to-day schedule that is different from your parenting plan for a while, it’s a good idea to get it formally modified accordingly, otherwise, if and when you and the other parent aren’t seeing eye to eye you will have to revert to the old plan that might not fit well anymore.