Find us on Google+

Leap Day…Why Does It Exist?

Once every four years, an extra calendar day is added: a leap day. But why?

The reason for adding leap days to the calendar is to align the calendar year with the actual year – which is defined by the time it takes Earth to circle the sun. It is equal to 365 days, 5 hours, 48 minutes and 46 seconds, or 365.24219 days.

image

If all calendar years contained exactly 365 days, they would drift from the actual year by about 1 day every 4 years. Eventually, July would occur during the northern hemisphere winter! Wouldn’t that be weird?

To correct (approximately), we add 1 day every 4 years…resulting in a leap year.

image

By making most years 365 days but every fourth year 366 days, the calendar year and the actual year remain more nearly in step.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Source: NASA

by
Leap Day…Why Does It Exist?

Posted in NASA and tagged by with no comments yet.

Leave a Reply

Your email address will not be published. Required fields are marked *