Why Do We Have Leap Years?

So its February 29th and we have 366 days this year instead of 365- whats the deal with Leap Years? ---------- Support SciShow by becoming a patron on .
Every four years, we get an extra day in February. Who decided this, and whats the point? Why Do We Have Days Of The Week?
You probably know that 2012 is a leap year. And that means that this year we get an extra day on February 29th. Great--an extra day. Who really cares? Well .
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