Spring Equinox 2025 Usa. An equinox is one of two days in the year when the sun crosses the equator and day and night become equal in length. Spring equinox 2025 (beginning of astronomical spring) on the day of the spring (march) equinox, the sun crosses the celestial equator, moving along the ecliptic.
Equinox means equal day and night (12 hours each). *the eastern time zone readings are already adjusted for edt or est.
