Day and Date Calculations — Mains Strategy

Mains Strategy

The written exercises are reasoning practice for an objective CSAT skill, not a descriptive Mains component. A clear response should make the day count reproducible. State the calendar, identify the direction of the interval, show its month or year segments and reduce the total modulo seven. Finish by translating the remainder into a weekday without changing the counting convention halfway through.

For a leap-day comparison, the most useful explanation identifies the location of 29 February relative to the endpoints. Merely saying that one year is a leap year does not establish the interval length. Compare March-to-March intervals on either side of 2024 to show why one contains 366 days and the next 365.

For an error-analysis question, diagnose the precise step: using a common-year February, counting both endpoints, moving in the wrong direction or ignoring a century exception. This is more informative than presenting a corrected weekday alone. A short independent check with a nearby date can confirm the method and expose a transcription error before the final answer is selected.