介绍:
A year is how long it takes for the Earth to orbit the Sun exactly once. So while the Earth orbits around the Sun in a full year, it spins around 365.25 times. In other words, one full year equals 365.25 days. This is called the astronomical year. But here is the problem, calendar year is only 365 days. And that’s because there’s really no way to have a 0.25 day. And so those extra 0.25 days, they just keep accumulating. And what they do is make it so that the stars slowly drift out of sync with our calendar. So this is where Leap Year comes in to save the day.
一年就是地球围绕太阳运行刚好一周的时间，但其实在一整年时间里，地球绕太阳要自转365.25圈。换句话说，一整年应该是365.25天，这叫做天文年。不过问题来了，日历当中只有365天，因为不可能有0.25天。每年多出来的这0.25天，就一直积累起来。而这样就使天上的星星渐渐变得和我们的日历不同步了。这时候我们就需要引入闰年来拯救天数了。
