Will date-book for the year 2003 serve for the year 2014?
Sum of odd days from 2003 to 2013 should be zero.
From 2003 to 2013, no of odd days are 1,2,1,1,1,2,1,1,1,2,1 respectively.
Sum of odd days = 1+2+1 + 1 + 1 + 2 + 1 + 1+1+2+1 = 2 week 0 odd days.
So, both dates 1.1.2009 and 1.1.2015 will be on same day, so calendar for the year 2003 will serve for the year 2014.