I hope you haven't thrown away all your nice calendars from the 1900's (Twentieth Century). You can reuse them in in the Twenty First, the "Oh Oh's". You have a pile in that spare bedroom closet that you saved because you wanted to frame one of the pictures, don't you? See if there is a 1972 in there somewhere. Hang it up at work and explain "It's the same as 2000." Impress your co-workers with your savant calendrical ability. Amaze your dentist next year by telling him you had an appointment on a certain day eleven years ago. Enjoy eleven year old calendar graffiti memories.

You can reuse calendars in 6 or 11 years, depending on leap year patterns. The first year after a Leap Year is the same as the calendar 11 years before or 6 years after. The second is the same as 11 years before or after. Leap Years repeat every 28 years The third year is like 6 years before or 11 years after. Use the chart below to plan ahead so you can give old calendars as gifts to those special family members.
 

January 1st  Year  Identical Year   Jan-Feb Only   Mar-Dec Only

Saturday     2000   1972, 2028         1994           1995
Monday       2001   1990, 2007
Tuesday      2002   1991, 2013
Wednesday    2003   1997, 2014
Thursday     2004   1976, 2032         1998           1999
Saturday     2005   1994, 2011
Sunday       2006   1995, 2017
Monday       2007   2001, 2018
Tuesday      2008   1980, 2036         2002           2003
Thursday     2009   1998, 2015
Friday       2010   1999, 2021
Saturday     2011   2005, 2022
Sunday       2012   1984, 2040         2006           2007
Tuesday      2013   2002, 2019
Wednesday    2014   2003, 2025
Thursday     2015   2009, 2026
Friday       2016   1988, 2044         2010           2011
Sunday       2017   2006, 2023
Monday       2018   2007, 2029
Tuesday      2019   2013, 2030