Calendar— Concepts, Formulas & Shortcuts
- Odd days = remainder when the number of days is divided by 7. Ordinary year = 1 odd day, leap year = 2.
- A year is a leap year if divisible by 4, except century years, which must be divisible by 400 (1900 was not a leap year, 2000 was).
- 100 years → 5 odd days, 200 → 3, 300 → 1, 400 → 0. The whole calendar repeats every 400 years.
- Day codes: 0 = Sunday, 1 = Monday, 2 = Tuesday … 6 = Saturday.
- An ordinary year's calendar repeats after 6 or 11 years; a leap year's after 28 years.
- Month odd days: Jan 3, Feb 0 (1 in a leap year), Mar 3, Apr 2, May 3, Jun 2, Jul 3, Aug 3, Sep 2, Oct 3, Nov 2, Dec 3.
Calendar Practice Questions with Answers
Attempt each question first, then open the explanation. All 21 questions below are free to read and require no signup.
Q1.The number of odd days in 100 years is:
Moderate- A0
- B3
- C5
- D6
Calendar question 1 of 21+Show Answer & Explanation
Answer: C. 5
Explanation: 100 years contain 24 leap years and 76 ordinary years → 24 × 2 + 76 = 124 days ≡ 124 mod 7 = 5 odd days.
Q2.The number of odd days in 400 years is:
Moderate- A0
- B1
- C3
- D5
Calendar question 2 of 21+Show Answer & Explanation
Answer: A. 0
Explanation: 400 years contain 97 leap years and 303 ordinary years → 497 days ≡ 0 mod 7. This is why the calendar repeats exactly every 400 years.
Q3.1 January 2026 is a Thursday. What day of the week is 1 January 2027?
Easy- AThursday
- BFriday
- CSaturday
- DSunday
Calendar question 3 of 21+Show Answer & Explanation
Answer: B. Friday
Explanation: 2026 is an ordinary year (365 days = 1 odd day), so the weekday advances by one → Friday.
Q4.Given that 1 January 2026 is a Thursday, Republic Day (26 January 2026) falls on a:
Moderate- ASaturday
- BSunday
- CMonday
- DTuesday
Calendar question 4 of 21+Show Answer & Explanation
Answer: C. Monday
Explanation: From 1 to 26 January is 25 days later; 25 mod 7 = 4, so Thursday + 4 = Monday.
Q5.How many leap years are there in the 100 years from 1801 to 1900?
Difficult- A23
- B24
- C25
- D26
Calendar question 5 of 21+Show Answer & Explanation
Answer: B. 24
Explanation: The multiples of 4 from 1804 to 1900 number 25, but 1900 is a century year not divisible by 400 and so is NOT a leap year — leaving 24. (By contrast 1901–2000 has 25, because 2000 is divisible by 400.)
Q6.The calendar for the year 2026 will repeat again in the year:
Difficult- A2032
- B2035
- C2037
- D2040
Calendar question 6 of 21+Show Answer & Explanation
Answer: C. 2037
Explanation: Cumulative odd days from 2026 to 2036 total 14 ≡ 0 mod 7, and 2037 is also an ordinary year like 2026 — so the calendar repeats after 11 years, in 2037.
Q7.Which of the following is NOT a leap year?
Easy- A2024
- B2028
- C2100
- D2400
Calendar question 7 of 21+Show Answer & Explanation
Answer: C. 2100
Explanation: 2100 is a century year not divisible by 400, so it is an ordinary year despite being divisible by 4.
Q8.How many odd days are there in an ordinary year?
Easy- A0
- B1
- C2
- D3
Calendar question 8 of 21+Show Answer & Explanation
Answer: B. 1
Explanation: 365 days = 52 weeks + 1 day, so an ordinary year has 1 odd day.
Q9.How many odd days are there in a leap year?
Easy- A0
- B1
- C2
- D3
Calendar question 9 of 21+Show Answer & Explanation
Answer: C. 2
Explanation: 366 days = 52 weeks + 2 days, so a leap year has 2 odd days.
Q10.The number of odd days in 200 years is:
Moderate- A1
- B3
- C5
- D6
Calendar question 10 of 21+Show Answer & Explanation
Answer: B. 3
Explanation: 100 years give 5 odd days, so 200 years give 10 ≡ 3 odd days (mod 7).
Q11.Which of the following is a leap year?
Easy- A2026
- B2027
- C2028
- D2029
Calendar question 11 of 21+Show Answer & Explanation
Answer: C. 2028
Explanation: 2028 is divisible by 4 and is not a century year, so it is a leap year.
Q12.If 15 August 2026 falls on a Saturday, then 15 September 2026 falls on a:
Moderate- AMonday
- BTuesday
- CWednesday
- DThursday
Calendar question 12 of 21+Show Answer & Explanation
Answer: B. Tuesday
Explanation: August has 31 days, and 31 mod 7 = 3, so the weekday advances by 3: Saturday + 3 = Tuesday.
Q13.How many days are there in 4 consecutive years, one of which is a leap year?
Easy- A1,460
- B1,461
- C1,462
- D1,464
Calendar question 13 of 21+Show Answer & Explanation
Answer: B. 1,461
Explanation: 3 × 365 + 366 = 1,461 days.
Q14.The last day of a century cannot be a:
Difficult- AMonday
- BTuesday
- CFriday
- DSunday
Calendar question 14 of 21+Show Answer & Explanation
Answer: B. Tuesday
Explanation: A century can end only on a Monday, Wednesday, Friday or Sunday — never on a Tuesday, Thursday or Saturday.
Q15.February 2028 will have how many days?
Easy- A28
- B29
- C30
- D31
Calendar question 15 of 21+Show Answer & Explanation
Answer: B. 29
Explanation: 2028 is a leap year, so February has 29 days.
Q16.How many odd days are there in 300 years?
Moderate- A0
- B1
- C3
- D5
Calendar question 16 of 21+Show Answer & Explanation
Answer: B. 1
Explanation: 100 years give 5 odd days, so 300 give 15 ≡ 1 odd day (mod 7).
Q17.If 1 March 2026 is a Sunday, then 1 April 2026 is a:
Moderate- ATuesday
- BWednesday
- CThursday
- DFriday
Calendar question 17 of 21+Show Answer & Explanation
Answer: B. Wednesday
Explanation: March has 31 days and 31 mod 7 = 3, so Sunday + 3 = Wednesday.
Q18.Which century year is a leap year?
Easy- A1700
- B1800
- C1900
- D2000
Calendar question 18 of 21+Show Answer & Explanation
Answer: D. 2000
Explanation: A century year must be divisible by 400; only 2000 qualifies.
Q19.How many days are there in a leap year?
Easy- A364
- B365
- C366
- D367
Calendar question 19 of 21+Show Answer & Explanation
Answer: C. 366
Explanation: A leap year has 366 days, with February gaining an extra day.
Q20.If today is Wednesday, what day will it be after 100 days?
Moderate- AThursday
- BFriday
- CSaturday
- DSunday
Calendar question 20 of 21+Show Answer & Explanation
Answer: B. Friday
Explanation: 100 mod 7 = 2, so Wednesday + 2 = Friday.
Q21.The number of odd days in a century that contains 24 leap years is:
Difficult- A3
- B4
- C5
- D6
Calendar question 21 of 21+Show Answer & Explanation
Answer: C. 5
Explanation: 24 × 2 + 76 × 1 = 124 days ≡ 124 mod 7 = 5 odd days.
Calendar — Frequently Asked Questions
What exactly is an odd day?+
The number of days left over after counting complete weeks. An ordinary year has 365 days = 52 weeks + 1 day, so it has 1 odd day; a leap year has 2. Adding odd days tells you how far the weekday has shifted.
Why was 1900 not a leap year?+
Century years are leap years only if divisible by 400. 1900 ÷ 400 leaves a remainder, so it was an ordinary year, whereas 2000 was a leap year.
Cleared the aptitude round? Now grab the role.
Preparation only pays off when you apply. Thousands of internships and fresher jobs across India are live on MyInternships.in right now — free to apply, no consultancy fees.