We teach quite a few tools about how to resolve conflict, but most of the time it is easier to just minimize conflict. Having a shared calendar is one way to minimize conflict over schedules.
We’ve learned over the years from talking with couples that they can get frustrated with one another because they have forgotten to share appointments or events they have coming up in a week. They swear they have told each other and accuse the other person of not paying attention. And then it goes downhill from there. Having a calendar system that works for you and your spouse is one of those simple things that can help minimize conflict.
Sharon and I use a calendar app called Cozi.com. Because she is more organized than I am she keeps the master calendar and I text her my appointments which she then enters into Cozi. Cozi then syncs across our many phones and devices so at any point in time either of us can look and see what the other has going on. (Or even where they are when you forget!) Just keeping a shared calendar helps keep misunderstandings and frustrations from happening.
Many couples or families use apps from Apple or Google. What apps or systems have you found that work for you to minimize calendar conflicts with your spouse or family?