Start Of Spring 2024 Date. 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 starts at the moment when the sun is directly over the equator, going from south to north:

This date marks the spring equinox in the northern hemisphere. Spring begins with the vernal equinox, tuesday, march 19, 2024, 11:06 p.m.