The year 2004 is a leap year. So, it has 2 odd days.

But, Feb 2004 not included because we are calculating from March 2004 to March 2005. So it has 1 odd day only.

The day on 6^th March, 2005 will be 1 day beyond the day on 6^th March, 2004.

Given that, 6^th March, 2005 is Monday.

6^th March, 2004 is Sunday (1 day before to 6^th March, 2005).

1^st April, 2001 = (2000 years + Period from 1.1.2001 to 1.4.2001)

Odd days in 1600 years = 0

Odd days in 400 years = 0

Jan. Feb. March April
(31 + 28 + 31 + 1)     = 91 days 0 odd days.

Total number of odd days = (0 + 0 + 0) = 0

On 1^st April, 2001 it was Sunday.

In April, 2001 Wednesday falls on 4^th, 11^th, 18^th and 25^th.

100 years contain 5 odd days.

Last day of 1^st century is Friday.

200 years contain (5 x 2) 3 odd days.

Last day of 2^nd century is Wednesday.

300 years contain (5 x 3) = 15 1 odd day.

Last day of 3^rd century is Monday.

400 years contain 0 odd day.

Last day of 4^th century is Sunday.

This cycle is repeated.

Last day of a century cannot be Tuesday or Thursday or Saturday.

x weeks x days = (7x + x) days = 8x days.

The year 2004 is a leap year. It has 2 odd days.

The day on 8^th Feb, 2004 is 2 days before the day on 8^th Feb, 2005.

Hence, this day is Sunday.