Question

20 марта в 2009 году пришлось на пятницу .На какой день недели пришлось 6 апреля в 2009 году? В марте 31 день.

Answer 1

20марта,27марта и 3 апреля-пятница.Значит 6 апреля-понедельник.

Answer 2

Calculation of the Day of the Week

To determine the day of the week for April 6, 2009, we can use the Zeller's Congruence algorithm. This algorithm allows us to calculate the day of the week for any given date.

The formula for Zeller's Congruence is as follows:

h = (q + [(13(m + 1)) / 5] + K + [K / 4] + [J / 4] - 2J) % 7

Where: - h is the day of the week (0 = Saturday, 1 = Sunday, 2 = Monday, ..., 6 = Friday) - q is the day of the month - m is the month (3 = March, 4 = April, ..., 12 = December) - K is the year of the century (year % 100) - J is the zero-based century (actually floor(year / 100))

Let's calculate the day of the week for April 6, 2009, using this formula.

Calculation:

- q = 6 (day of the month) - m = 4 (April) - K = 9 (2009 % 100) - J = 20 (floor(2009 / 100))

Substituting these values into the formula:

h = (6 + [(13(4 + 1)) / 5] + 9 + [9 / 4] + [20 / 4] - 2 * 20) % 7

Simplifying the equation:

h = (6 + [65 / 5] + 9 + 2 + 5 - 40) % 7

h = (6 + 13 + 9 + 2 + 5 - 40) % 7

h = (35) % 7

h = 0

The value of h is 0, which corresponds to Saturday. Therefore, April 6, 2009, fell on a Saturday.

Please note that the above calculation is based on the Gregorian calendar system, which is the most widely used calendar system today.