When Is Spring Equinox 2027. The vernal (spring) equinox is when the sun crosses the earth’s equator, making day and night equal. Equinox means equal day and night (12 hours each).
Spring equinox 2027 (beginning of astronomical spring) on the day of the spring (march) equinox, the sun crosses the celestial equator, moving along the ecliptic. The times of the equinoxes mark the beginning of spring and fall.