Book 1, Question 90
Why Do We Have Leap Years? That Extra Quarter Day!
A year on Earth is about 365 and a quarter days, and that extra quarter adds up. Every four years, we add an extra day, February 29, which keeps the seasons in place. The page adds that we skip the extra day in some century years, like 1900 and 2100, unless the year is divisible by 400, like 2000. Try the math: add 0.25 four times and you get one whole extra day!
From the book
Page from A Million Whys Book 1
More fun facts
- If your birthday is February 29, you were born on a leap day. Your real birthdate only comes around about once every four years.
- The year that controls the seasons is about 365.2422 days long.
- Without leap years, the missing hours would add up to days, weeks and even months, and the calendar would drift away from the seasons.
- If the calendar didn't match the seasons, farmers would have a harder time growing crops.
- Long ago, Julius Caesar fixed the Roman calendar with a year so long it was nicknamed the Year of Confusion.
- By the 1500s, important dates had still drifted by 10 days, so a new calendar was made: the Gregorian calendar we use today.
- When ancient Egyptians had a calendar that came up short, they added five days of parties at the end of the year.
Sources: NASA Space Place, National Geographic Kids
Questions kids ask
What happens if you are born on February 29?
You were born on a leap day, so your real birthdate shows up only about once every four years.
What would happen without leap years?
The calendar would slowly drift away from the seasons.