1. What is a Leap Year?

A leap year is a year containing one additional day (February 29) to keep the calendar year synchronized with the astronomical year. The Gregorian calendar uses specific rules to determine which years are leap years.

2. How Does the Calculator Work?

The calculator uses the leap year formula:

Where:

• Divisible by 400 — Always a leap year
• Divisible by 100 — Not a leap year (unless also divisible by 400)
• Divisible by 4 — Leap year (unless divisible by 100)

Explanation: The rules account for the fact that a solar year is approximately 365.2422 days long.

3. Importance of Leap Years

Details: Without leap years, our calendar would drift by about 1 day every 4 years, causing seasons to gradually shift over time.

4. Using the Calculator

Tips: Enter any year (positive integer) to check if it's a leap year according to Gregorian calendar rules.

5. Frequently Asked Questions (FAQ)

Q1: Why do we skip some leap years?
A: Years divisible by 100 are skipped unless divisible by 400 to correct for the overcompensation of adding a leap day every 4 years.

Q2: Was 2000 a leap year?
A: Yes, because although divisible by 100, it's also divisible by 400.

Q3: Will 2100 be a leap year?
A: No, because it's divisible by 100 but not by 400.

Q4: How accurate is this system?
A: The Gregorian calendar averages 365.2425 days per year, very close to the solar year of 365.2422 days.

Q5: What calendar was used before this system?
A: The Julian calendar had simpler rules (leap year every 4 years) which caused about 11 minutes of drift per year.