For purposes of calendar repetition, the complete calendar for the year 2018 (same days and dates arrangement) will be exactly the same for which of the following later years?

Aptitude Calendar Difficulty: Medium
Choose an option
  • A
    2023
  • B
    2027
  • C
    2029
  • D
    2022
  • E
    2034

Answer

Correct Answer: 2029

Explanation

Introduction: Calendar repetition questions ask in which future year the same arrangement of days and dates will reappear. For example, 1 January must fall on the same weekday, and the year type (leap year or non-leap year) must also match. Here we need the year whose calendar is identical to that of 2018.

Given Data / Assumptions: Base year = 2018. 2018 is a non-leap year (since it is not divisible by 4). We want the next future year with: (a) Same year type (non-leap). (b) Same weekday for 1 January, and hence the same pattern for all dates.

Concept / Approach: Each non-leap year advances the starting weekday of the next year by 1 day (since 365 ≡ 1 mod 7). Each leap year advances it by 2 days (since 366 ≡ 2 mod 7). To find when the calendar repeats, we track the cumulative shift in weekdays from 2018 onward and look for a non-leap year where the total shift is a multiple of 7 days, so that 1 January falls on the same weekday again.

Step-by-Step Solution: Step 1: Identify leap and non-leap years after 2018. 2019: non-leap, shift +1 day. 2020: leap, shift +2 days. 2021: non-leap, shift +1 day. 2022: non-leap, shift +1 day. 2023: non-leap, shift +1 day. 2024: leap, shift +2 days. 2025, 2026, 2027, 2028, etc. continue similarly. Step 2: Track cumulative shift until it is a multiple of 7 and the year is non-leap. From 2018 to 2029, the cumulative shift adds up to 14 days, which is exactly 2 full weeks (14 ≡ 0 mod 7). Also, 2029 is a non-leap year. Therefore, 2018 and 2029 have identical calendars.

Verification / Alternative check: Instead of tracking every year manually, one can remember that non-leap year calendars usually repeat every 11, 6, and 11 years (in a 28-year cycle), depending on positions of leap years. Starting from 2018, adding 11 gives 2029, which fits the pattern and is non-leap, confirming the result.

Why Other Options Are Wrong: 2023: Weekday pattern does not match 2018 exactly. 2027: Also does not align with both the first weekday and leap/non-leap structure. 2022: The weekday of 1 January differs from that in 2018. 2034: Occurs later in the repetition cycle and does not give the earliest match.

Common Pitfalls: Learners often assume that calendars repeat every 11 years automatically, forgetting that leap years disturb this simple repetition. Always check both the total weekday shift and the leap-year status of the target year.

Final Answer: The calendar for the year 2018 repeats in 2029.

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