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Day After/Before

Day After/Before problems ask: 'What day will it be N days after a given day?' or 'What day was it N days ago?' These problems test your understanding of the weekly cycle and modular arithmetic.

10Worksheets
200+Practice Questions
BeginnerDifficulty
1 hourHours 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 Day After/Before

Day After/Before problems ask: 'What day will it be N days after a given day?' or 'What day was it N days ago?' These problems test your understanding of the weekly cycle and modular arithmetic.

Prerequisites

Days of week order Modulo 7 arithmetic Understanding of 'after' (future) and 'before' (past) concepts
Why This Matters: Day After/Before problems appear frequently in calendar sections. You can expect 1-2 questions in SSC CGL and Banking PO prelims.

How to Solve Day After/Before Problems

1

Step 1: Identify the given day and the offset (N days)

2

Step 2: Determine direction: 'after' means future, 'before' means past

3

Step 3: Calculate odd days = N mod 7

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Step 4: For 'after': add odd days to the given day's position number

5

Step 5: For 'before': subtract odd days from the given day's position number

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Step 6: If result goes beyond 0-6 range, adjust by adding or subtracting 7

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Step 7: Convert the resulting number back to the day name

Pro Strategy: Reduce the offset to its remainder when divided by 7 (odd days). Add for future, subtract for past. Remember that the days repeat every 7 days.

Example Problem

Example 1: If today is Wednesday, what day will it be 15 days from now? Solution: Step 1: Given day = Wednesday (position 2 if Monday=0, or use direct) Step 2: Direction: after (future) Step 3: Odd days = 15 mod 7 = 1 Step 4: Wednesday + 1 day = Thursday Answer: Thursday Example 2: If today is Sunday, what day was it 25 days ago? Solution: Odd days = 25 mod 7 = 4. Sunday - 4 days = Wednesday Answer: Wednesday

Pro Tips & Tricks

  • Any multiple of 7 days brings you back to the same day
  • Odd days = N mod 7 (remainder when divided by 7)
  • For 'after', move forward in the week cycle
  • For 'before', move backward in the week cycle
  • Common mappings: 1 day after = next day, 2 days after = day after next
  • Use the rule: 7 days later = same day

Shortcut Methods to Solve Faster

Day after N days = (Given day position + N) mod 7
Day before N days = (Given day position - N) mod 7
If N is a multiple of 7, answer = given day
N = 7k + r → shift by r days only

Common Mistakes to Avoid

Adding/subtracting the full N instead of N mod 7
Confusing 'after' with 'before' direction
Using incorrect day numbering (0 vs 1 based)
Forgetting that week cycles every 7 days

Exam Importance

Day After/Before 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
2-3 questions
CAT
0-1 questions
INSURANCE
1-2 questions

Ready to Master Day After/Before?

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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