On 23rd Jan, 2005 it was Sunday. What was the day of the week on 23rd Jan, 2004 ?

The logic follows here is:

In an ordinary year, there are 365 days and on dividing 365 by 7,

we get remainder = 1 so this extra one day is taken as an odd day.

Similarly, in a leap year, there are 366 days and on dividing 366 by 7,

we get remainder = 2 so these extra days are taken as the odd days.

Thus, the remainder, which we get after dividing the number of days by 7 is considered as odd days.

As 23rd January, 2005, which was Sunday.

Since 2004 is a leap year,

There are 366 days between 23rd January, 2004 and 23rd January, 2005.

When 366 is divided by 7,

The remainder is 2.

As we are calculating day in reverse.

Thus 2 day before Sunday.

So if 23rd January, 2005 was on Sunday,

23rd January, 2004 was be on Friday.

Hence, the correct answer is "Friday".