Try getting a whiteboard calendar. We had one that was just one month and it got a lot of mileage in our household. Underneath was a second blank whiteboard that was roughly the same size. We used that one to write down dates of events that weren't in the current month. Both of the whiteboards had a lot of space for writing stuff down.

You'll want to clean it off every few months with isopropyl alcohol. When I cleaned it I would take a picture beforehand and write everything back down again.

Best part? You'll only need to buy the whiteboards once.