Whether the groundhogs saw their shadows or not, here's when the real first day of spring will be, according to NASA.

The first day of spring is closer than you might think.

Winter in the northern hemisphere and summer in the southern hemisphere are both coming to an end. That means the days and nights are becoming roughly equal in length, and the path the Sun traces ...

Day and night will get equal time for a brief moment Monday as much of the world heads into fall. The autumnal equinox arrives Monday, marking the start of the fall season for the Northern Hemisphere ...