Skip to main content

Why do we have leap years?

432,567 Views

2,994 Questions Answered

Best of Web

Let’s Begin…

Every four years, we gain an extra calendar day. Why is that? SciShow explains.

What invention made it important to keep track of each day of the year?

About TED-Ed Best of Web

TED-Ed Best of Web are exceptional, user-created lessons that are carefully selected by volunteer teachers and TED-Ed staff.

Meet The Creators

More from How Things Work