Josh Lyons: Calendars can be recycled. Just update those from lunar calendars that wander around the Gregorian one, like Yom Kippur, Easter, and Ramadan. 2014 will come around again in 2025. They repeat in a 6, 5, 6, 11 cycle. If you have a 2009 calendar, it will be usable for 2015. Leap day is what throws it off from just regressing one day per year.