The day of 6^th April 2001 was _____.

Given:

The day of 6th April 2001 was _____.

Formula used:

To find the day of the week for any given date, we can use the formula:

Zeller's Congruence:

h = (q + ⌊(13(m + 1)/5)⌋ + K + ⌊K/4⌋ + ⌊J/4⌋ - 2J) mod 7

Where,

h = day of the week (0 = Saturday, 1 = Sunday, 2 = Monday, ..., 6 = Friday)

q = day of the month

m = month (3 = March, 4 = April, ..., 12 = December; January and February are counted as months 13 and 14 of the previous year)

K = year of the century (i.e., year mod 100)

J = zero-based century (i.e., ⌊year / 100⌋)

Calculation:

For 6th April 2001:

q = 6

m = 4

Year = 2001, so K = 01 and J = 20

h = (6 + ⌊(13(4 + 1)/5)⌋ + 01 + ⌊01/4⌋ + ⌊20/4⌋ - 2 × 20) mod 7

⇒ h = (6 + ⌊65/5⌋ + 1 + ⌊1/4⌋ + 5 - 40) mod 7

⇒ h = (6 + 13 + 1 + 0 + 5 - 40) mod 7

⇒ h = (25 - 40) mod 7

⇒ h = (-15) mod 7

⇒ h = (-15 + 21) mod 7

⇒ h = 6 mod 7

⇒ h = 6

Therefore, h = 6, which corresponds to Friday.

∴ The correct answer is option 2.