The Science of Accuracy

Accuracy is the cornerstone of BirthdayChecker. Our system uses the Gregorian Calendar algorithm, the international standard for civil timekeeping since its introduction in 1582.

Precision Leap Year Logic

To maintain astronomical synchronization, we apply the three-part rule for leap years:

• A year is a leap year if it is evenly divisible by 4.
• However, if it is evenly divisible by 100, it is NOT a leap year...
• ...UNLESS it is also evenly divisible by 400. In that case, it is a leap year.

This refined rule set ensures that the average length of a calendar year is 365.2425 days. This precision is a cornerstone of modern timekeeping and ensures your "Life Odometer" is accurate to the day.