First Fix: The "Every 4 Years" Rule

Last updated at August 10, 2026 by

First Fix: The "Every 4 Years" Rule - Teachoo - Look Before You Leap! - Look Before You Leap!

part 2 - First Fix: The "Every 4 Years" Rule - Look Before You Leap! - Chapter 4 Class 7 - Another Peek beyond the Point (Ganita Prakash II) - Class 7 (Ganita Prakash 1, 2 & old NCERT)

Remove Ads
Teachoo · Class 7 Explore Class 7

Transcript

First Fix: The "Every 4 Years" RuleTo catch up, mathematicians decided to add one extra day every four years (Leap Year). The Math: 0.2422 × 4 = 0.9688 days. By adding 1 full day (Feb 29th), we almost fix the problem. But wait! Adding a full day (1.0) when we only needed 0.9688 means we added slightly too much time (about 0.03 days too many). This is called overcompensating. How we realized it was a problem? If you add 0.0312 extra days every 4 years, After 400 years, that error grows: (400÷4) × 0.0312=𝟑.𝟏𝟐 days The calendar was 𝟑 days ahead of the Sun! So, we added another fix

CA Maninder Singh's photo - Co-founder, Teachoo

Made by

CA Maninder Singh

CA Maninder Singh is a Chartered Accountant with 16+ years of practical experience and 20+ years of teaching experience. At Teachoo, he simplifies Accounts, Tax and GST with step-by-step examples so students can apply concepts confidently in exams and real life.

For an uninterrupted learning experience, students can use Teachoo Black to remove ads and focus better.