These are the historically universal and still most widely used terms for the equinoxes , but are potentially confusing .
In the southern hemisphere the vernal equinox does not occur in spring and the autumnal equinox does not occur in autumn .
These are the historically universal and still most widely used terms for the equinoxes , but are potentially confusing because in the southern hemisphere the vernal equinox does not occur in spring and the autumnal equinox does not occur in autumn .