Kid schedules are hard enough to follow without factoring in two or more households, child handovers, visitations and multiple calendars. A good option is to start an online calendar that all parties can access. Appointments can be scheduled with notices and reminders going out via email, and entries can even be color coded as to who is picking up or dropping off the kids.
This is also possibly a good solution if there are contact restrictions or conflict between parents, so scheduling can be solidified without direct contact between the parties. Talk to your attorney or the courts before starting a joint calendar if there is a restraining order or order of protection in effect.