CCommunity
Number of odd days in 2009 = 1
Number of odd days from 2009 till 2010 = 1 + 1 = 2 odd days
Number of odd days from 2009 till 2011 = 2 + 1 = 3 odd days
Number of odd days from 2009 till 2012 = 3 + 2 = 5 odd days
Number of odd days from 2009 till 2013 = 5 + 1 = 6 odd days
Number of odd days from 2009 till 2014 = 6 + 1 = 7 odd days = 0 odd days
Hence, 1st February 2015 will be Sunday.