Decode the day for the given date

1

What is the day of the week for 15th August 1947?

A. Thursday B. Friday C. Saturday D. Sunday

Show Answer

✔ Correct: B

Using the formula: (Date + Month Code + Year Code + Century Code + Leap Year count)/7. Date=15, Month=2, Century=0, Year=47, Leap=11. (15+2+47+0+11) = 75. 75 mod 7 = 5. 5 corresponds to Friday.

2

Which of the following is the century code for years 2000-2099?

A. 0 B. 6 C. 4 D. 2

Show Answer

✔ Correct: B

Century codes repeat every 400 years: 1600-1699 is 6, 1700-1799 is 4, 1800-1899 is 2, 1900-1999 is 0, 2000-2099 is 6.

3

What is the leap year count for the year 2024?

A. 5 B. 6 C. 24 D. 4

Show Answer

✔ Correct: B

Divide the last two digits of the year by 4. 24 / 4 = 6.

1

Assertion (A): The month code for January in a non-leap year is 0.
Reason (R): Month codes are derived from the number of days in each month modulo 7.

Directions: Choose the correct option:
(A) Both A and R are true and R is the correct explanation of A.
(B) Both A and R are true but R is not the correct explanation of A.
(C) A is true but R is false.
(D) A is false but R is true.

A. Option A B. Option B C. Option C D. Option D

Show Answer

✔ Correct: A

Both the assertion and reason are true, and the reason explains the origin of the code.

2

Assertion (A): A century year like 1900 is a leap year.
Reason (R): Century years must be divisible by 400 to be leap years.

Directions: Choose the correct option:
(A) Both A and R are true and R is the correct explanation of A.
(B) Both A and R are true but R is not the correct explanation of A.
(C) A is true but R is false.
(D) A is false but R is true.

A. Option A B. Option B C. Option C D. Option D

Show Answer

✔ Correct: D

Assertion is false as 1900 is not divisible by 400. Reason is true.

1

Find the day of the week for 26th January 2023.

Show Answer & Solution

Formula components: Date=26, Jan code=0 (non-leap), Year=23, Century code=6, Leap years in 23 = 5. Total = 26 + 0 + 23 + 6 + 5 = 60. 60 mod 7 = 4. 1=Sunday, 2=Monday, 3=Tuesday, 4=Thursday. So, it is Thursday.

2

Explain why the leap year code changes in January and February for leap years.

Show Answer & Solution

In a leap year, February has 29 days instead of 28. Since the day-of-the-week calculation accumulates these days, we subtract 1 from the standard codes for Jan (0 becomes 6) and Feb (3 becomes 2) to account for the leap day shift.

1

Calculate the day for 2nd October 1869 (Mahatma Gandhi's birth date).

Show Answer & Solution

Step 1: Date=2. Step 2: Month code for October=0. Step 3: Century code for 1800-1899=2. Step 4: Year=69. Step 5: Leap years in 69 = 69/4 = 17. Step 6: Sum = 2 + 0 + 2 + 69 + 17 = 90. Step 7: 90 mod 7 = 6. Mapping: 0=Sat, 1=Sun, 2=Mon, 3=Tue, 4=Wed, 5=Thu, 6=Fri. Therefore, the day was Saturday.

2

Explain the methodology to derive the day of the week for any given date in the 21st century (2000-2099).

Show Answer & Solution

1. Identify the date (D). 2. Use month codes (J:0, F:3, M:3, A:6, M:1, J:4, J:6, A:2, S:5, O:0, N:3, D:5). 3. Identify last two digits of year (Y). 4. Calculate Leap years (L = Y // 4). 5. Century code for 2000 is 6. 6. Sum = D + MonthCode + Y + L + 6. 7. Result = Sum mod 7. 8. Match result with: 0=Sat, 1=Sun, 2=Mon, 3=Tue, 4=Wed, 5=Thu, 6=Fri.

1

Case Study: A history student wants to verify the day of the week for major historical events. The reference table provided for the student includes Century Codes (1700: 4, 1800: 2, 1900: 0, 2000: 6) and Month Codes (Jan:0, Feb:3, Mar:3, Apr:6, May:1, Jun:4, Jul:6, Aug:2, Sep:5, Oct:0, Nov:3, Dec:5).

Sub-question 1: Using the passage, determine the day for 1st January 2000.

Show Solution

Date: 1, Month: 0, Year: 0, Leap: 0, Century: 6. Sum: 1+0+0+0+6 = 7. 7 mod 7 = 0. Based on standard mapping where 0 is Saturday, the day is Saturday.

Sub-question 2: If the student checks 1st January 1900, how will the century code change the calculation result?

Show Solution

The century code for 1900 is 0 instead of 6. Total = 1+0+0+0+0 = 1. 1 mod 7 = 1. Since 1 corresponds to Sunday, 1st January 1900 was a Monday (adjusting mapping) or simply Sunday depending on the specific starting index used for the week.

Fundamental Components of Calendar Calculations

Standard Reference Tables for Calculations

Section A: Multiple Choice Questions (MCQs)

Section B: Assertion-Reason Questions

Section C: Short Answer Questions

Section D: Long Answer Questions

Section E: Case-Based Questions

Dynamic Test Generator (Gemini Powered)