Q. The calendar for the year 2025 is same for
a) 2029
b) 2030
c) 2031
d) 2033
Correct answer: c) 2031
Question from UPSC Prelims 2024 CSAT Paper
Explanation:
Calendar Year 2025
1. First, let’s understand what “odd days” means:
– In a non-leap year, there are 365 days, which is 52 weeks + 1 day
– This extra 1 day is called an “odd day”
– In a leap year, there are 366 days, which is 52 weeks + 2 days (2 odd days)
2. Now, let’s count the odd days from 2025 to each of the given years:
2025 to 2029:
– 2025: 1 odd day
– 2026: 1 odd day
– 2027: 1 odd day
– 2028 (leap year): 2 odd days
Total: 5 odd days
2025 to 2030:
– Same as above + 1 more day for 2029
Total: 6 odd days
2025 to 2031:
– Same as 2030 + 1 more day for 2030
Total: 0 odd days (7 odd days = 1 week, so no change in calendar)
2025 to 2033:
– Same as 2031 + 1 day each for 2031 and 2032
Total: 2 odd days
3. For the calendar to be the same, we need 0 odd days (or a multiple of 7 odd days).
4. Looking at our results, only 2031 has 0 odd days.
Therefore, the correct answer is c) 2031.