Because 2024 is a leap year, the second month of the new year will have one extra day. While everyone knows that a leap year happens every four years, what precisely is a leap year? Why was it deemed necessary? Is there a leap year every four years? We’ll explain. A leap year has 366 days instead of the standard 365 days. The extra day is added to February, the year’s shortest month, as February 29. One year in a solar calendar corresponds to one orbit of the Earth around the Sun. The Earth revolves around the Sun in 365 days, 5 hours, 48 minutes, and 46 seconds. As a result, the duration of a typical year is rounded off to 365 days.
Every fourth year, 24 hours – one full day — are added to account for the extra time, rounded up to six hours. If this was not done, crop cycles and seasons would eventually begin to occur at different times of the year, confusing. Julius Caesar’s academics introduced the leap year in 46 BC, and it became more precise beginning in 12 AD. The Julian calendar featured a year that was 365 days long on average, with a 366th day added every four years. According to the Royal Museums Greenwich website, the Islamic calendar Al-Hijra adds an extra day to the 12th month of Zul Hijja on leap years.
Removing the leap year from all years ending in 00 would throw the math out of whack once more
Even this approach was not without flaws, as the six hours utilized for calculation differed from the actual 5 hours, 48 minutes, and 46 seconds, causing the calendar year to be somewhat longer than the solar year. Thus, in the 16th century, it was computed that the previous calendar years had accrued 10 extra days. In 1582, Pope Gregory XIII ordered a harsh compensation by removing ten days from the calendar, and October 4 that year was immediately followed by October 15.
Pope Gregory XIII’s one-time measure was insufficient to fix the problem. As a result, it was determined that some leap years — roughly one every century — would be dropped to accommodate the extra day. The years chosen for this were those ending with 00. However, removing the leap year from all years ending in 00 would throw the math out of whack once more. Finally, the 00 years that were divisible by 400 became leap years in the Gregorian calendar. As a result, while 1900 was not a leap year, 2000 was.
