Friday, March 20th 2015 6:45 AM — 7:00 AM
Vernal Equinox (First Day of Spring / Autumn 2015)
Astronomically speaking, the March equinox occurs when the Sun crosses the celestial equator on its way north along the ecliptic. In the Northern Hemisphere, the March equinox is known as the vernal, or spring, equinox, and marks the start of the spring season.
In the Southern Hemisphere, this equinox is known as the autumnal, or fall, equinox and marks the start of the fall season; the vernal equinox for the Southern Hemisphere occurs in September.
The March equinox happens at the same moment across the world but is converted to local time. In 2015, it falls on March 20 at 6:45 P.M. EDT, 5:45 P.M. CDT, 4:45 P.M. MDT, and 3:45 P.M. PDT, for example.