Equinoxes and Solstices of 2011.

2011年的春秋分和冬夏至。

We call the equinoxes spring and fall.

这两个分点，人们分别称之为春分和秋分。

He then accounts for the precession of the equinoxes.

然后他解释分点岁差。

In reality equinoxes don't have exactly 12 hours of daylight.

在现实中的春分、秋分不一定正好是12小时的白昼。

It is due to a phenomenon called the precession of the equinoxes.

这是由于岁差现象所导致。