Explanation : Odd days in 2007 = 1 (2007 is an ordinary year and we
are doing calculation from January 1)
Odd days in 2008 = 2 (2008 is a leap year)
Odd days in 2009 = 1 (ordinary year)
Odd days in 2010 = 1 (ordinary year)
Thus, January 1, 2011, will be Monday plus 5 days,
i.e., Saturday.