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Month-Day Pair

Month-Day Pair problems involve finding the weekday of a specific date in one month when the weekday of the same date in the previous or next month is known. These problems require calculating the shift caused by the number of days in the intervening month.

10Worksheets
200+Practice Questions
IntermediateDifficulty
2-3 hoursHours to Master

What You'll Learn

Introduction & Overview Why This Matters How to Solve Pro Tips & Tricks
Shortcut Methods Common Mistakes Practice Worksheets Exam Importance

Introduction to Month-Day Pair

Month-Day Pair problems involve finding the weekday of a specific date in one month when the weekday of the same date in the previous or next month is known. These problems require calculating the shift caused by the number of days in the intervening month.

Prerequisites

Knowledge of month lengths Understanding of weekday shift calculation Modular arithmetic Leap year awareness for February
Why This Matters: Month-Day Pair problems appear in 1-2 questions in SSC CGL and Banking PO exams. They test understanding of month length effects on weekday shifts.

How to Solve Month-Day Pair Problems

1

Step 1: Identify the reference month and date with known weekday

2

Step 2: Identify the target month with the same date number

3

Step 3: Calculate the number of days in the month(s) between them

4

Step 4: If target month is after reference month, add the days of intervening months to the known date's weekday

5

Step 5: If target month is before reference month, subtract the days of intervening months

6

Step 6: Apply modulo 7 to get the weekday shift

7

Step 7: If the date is 29th, 30th, or 31st, ensure the target month has that date

Pro Strategy: The weekday shift from same date in one month to next month depends only on the number of days in the first month. Shift = (days_in_first_month) mod 7. For non-leap February, shift = 28 mod 7 = 0; for leap February, shift = 29 mod 7 = 1.

Example Problem

Example: January 15 is Monday. What day is February 15 (non-leap year)? Solution: Step 1: January has 31 days Step 2: Days from Jan 15 to Feb 15 = 31 - 15 + 15 = 31 days Step 3: 31 mod 7 = 3 Step 4: Monday + 3 days = Thursday Answer: Thursday Example 2: March 10 is Tuesday. What day is April 10? Solution: Step 1: March has 31 days Step 2: Days from Mar 10 to Apr 10 = 31 - 10 + 10 = 31 days Step 3: 31 mod 7 = 3 Step 4: Tuesday + 3 = Friday Answer: Friday

Pro Tips & Tricks

  • January (31) → February: shift +3 days
  • February (28/29) → March: shift 0 (28) or +1 (29)
  • March (31) → April: shift +3
  • April (30) → May: shift +2
  • May (31) → June: shift +3
  • June (30) → July: shift +2

Shortcut Methods to Solve Faster

Same date next month = current weekday + (days_in_current_month mod 7)
Same date previous month = current weekday - (days_in_previous_month mod 7)
Shift values: 31-day month → +3, 30-day month → +2, 28-day Feb → 0, 29-day Feb → +1

Common Mistakes to Avoid

Forgetting that February has variable length (28 or 29)
Not handling date 31 when next month has only 30 days
Confusing which month's days to count
Adding instead of subtracting for previous month

Exam Importance

Month-Day Pair is an important topic for various competitive exams. Here's how frequently it appears:

SSC CGL
1-2 questions
BANKING PO
1-2 questions
RAILWAYS RRB
1-2 questions
INSURANCE
1-2 questions

Ready to Master Month-Day Pair?

Start with Worksheet 1 and work your way up to expert level! Each worksheet includes:

20 practice questions
Detailed solutions
Step-by-step explanations
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