If 5th March, 1999 was Friday, what day of the week was it on 9th March 2000?

5th March, 1999 is Friday.
Then, 5 March 2000 = Friday + 2 = Sunday
(2000 is leap year and it crosses 29th feb 2000, so 2 is taken as odd day}
∴ 5th March 2000 = Sunday
Then, 9th March 2000 = Thursday.