The two equinoxes happen in March (marking the start of spring in the Northern Hemisphere) and September (marking the start of autumn). At the moment of the equinox, the Earth's axis is not tilted toward or away from the sun, leading to nearly equal amounts of daylight and darkness.
What Is an Equinox?
An equinox is one of the two times each year when the Sun is positioned directly over the Earth's equator, resulting in a day and night of nearly equal length across the globe.
Quick Answer
An equinox happens twice a year, in March and September. It's the moment when the Sun is directly above the equator, and day and night are almost exactly equal in length everywhere on Earth. The March equinox marks the start of spring in the Northern Hemisphere, and the September equinox marks the start of autumn.
Related Questions
What is UTC (Coordinated Universal Time)?
UTC is the primary time standard by which the world regulates clocks. It's the successor to GMT and is based on atomic time for precision.
What is Daylight Saving Time (DST)?
DST is the practice of advancing clocks by one hour during warmer months to extend daylight into the evening.
What does GMT stand for?
GMT stands for Greenwich Mean Time, the historic time standard based on the Prime Meridian in Greenwich, London.
How many time zones are in the USA?
The USA and its territories use 9 standard time zones. The 4 contiguous US states time zones are Pacific, Mountain, Central, and Eastern.