Intercalation (timekeeping) facts for kids
A calendar is like a super organized planner that helps us keep track of time! It's usually based on how planets and moons move, especially the sun and the moon.
Sometimes, calendars need a little tweak to stay perfectly aligned with these movements. This tweak is called intercalation. It means adding an extra day, week, or even a month to the calendar.
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Why Calendars Need Extra Time
Think about the solar year, which is how long it takes for Earth to go all the way around the sun. It's about 365.25 days long. Our regular calendar, like the Gregorian calendar, usually has 365 days.
Leap Years in the Gregorian Calendar
To catch up with that extra quarter of a day each year, the Gregorian calendar adds an extra day almost every four years. This extra day is added to February, making it 29 days long instead of 28. This special year is called a leap year. Without leap years, our calendar would slowly get out of sync with the seasons!
Extra Months in the Jewish Calendar
The Jewish calendar is a bit different. It's a lunisolar calendar, which means it uses both the sun and the moon to keep time. A lunar month (how long it takes for the moon to go through all its phases) is about 29.5 days.
This creates a challenge because 12 lunar months don't quite make a full solar year. Twelve lunar months add up to about 354 days, which is shorter than the 365.25 days of a solar year. To fix this, the Jewish calendar sometimes adds an extra month. This helps keep the holidays and seasons in the right place each year.
See also
In Spanish: Embolismo para niños
