The March equinox will come on Thursday, March 20, 2025, at 9:01 UTC (4:01 a.m. CDT). It’s the Northern Hemisphere’s spring equinox and Southern Hemisphere’s autumn equinox.
You sometimes hear it said that, at the equinoxes, everyone receives about equal daylight and darkness. But there’s really more daylight than darkness at the equinox, eight more minutes or so at mid-temperate latitudes.
Two factors explain why we have more than 12 hours of daylight on this day of supposedly equal day and night. They are: 1. The sun is a disk, not a point. 2. Atmospheric refraction.
Bottom line: There’s slightly more day than night on the day of an equinox. That’s because the sun is a disk, not a point of light, and because Earth’s atmosphere refracts (bends) sunlight.