Realm revert to past save?

My wife and I play on Realms with 3 friends. We log in at roughly 8:30 pm central every night. Tonight when we logged in, we found that our realm has reverted to a previous save state. The temple I built last night was no longer built (the land I cleared for it was there again), my wife's underwater farm is just an empty room, the minecart system we had built a day or so ago is gone, out inventory since then is gone, and the mine we started is no longer even created.