Calendars don't really expire. The starting day of the year determines the layout of the months; So you really just need seven regular-year calendars. One that begins on Monday, Tuesday, Wednesday, Thursday, Friday, Saturday and Sunday.
Leap years mess things up. But you can handle leap years just by switching the calendar you use on March 1.
I've known people who recycle old calendars.
I didn't think of this. What a clever idea. Now I need 6 more. 5 after the Classic kittens and puppies.