The last day of year, 2006 was?

Last two digits of year : 06
Divided by 4 :01
Date: 31 (last day will be 31st Dec)
Month code : 6
Final value : 44
On dividing by 7, we get 2 as remainder. As year is between 2000 - 2099, so 1 has to be subtracted, now the result
= 2 - 1 = 1
1 is the day code for Sunday.