Solstice & Equinox Dates Calculator
Find the dates and times of solstices and equinoxes for any year.
How It Works
Solstices occur when the sun reaches its most northerly or southerly position. Equinoxes occur when day and night are equal length. Dates shift slightly each year due to the leap year cycle.
Formula
Summer Solstice ~June 21 | Winter Solstice ~Dec 21 | Equinoxes ~Mar 20 & Sep 23
Frequently Asked Questions
What is the summer solstice?
The summer solstice (around June 21 in the Northern Hemisphere) is the longest day of the year when the sun is at its most northerly point. It marks the astronomical start of summer.
What is the equinox?
At an equinox the sun is directly over the equator and day length equals night length (approximately 12 hours each) at all latitudes.