![]() ![]() Today's Gregorian calendar has 365 days in a common year and 366 days in a leap year. The date of the equinoxes and solstices varies because a year in our calendar does not exactly match the length of the tropical year-the time it takes the Earth to complete an orbit around the Sun. The equinox in September is the start of fall in the Northern Hemisphere and the beginning of spring south of the equator.Įquinox and solstice dates-years 1-2149 Why Does the Date Vary? The March and September equinoxes mark the beginning of the spring and autumn seasons on Earth, according to one definition. In reality, equinox days don’t have exactly 12 hours of daylight and 12 hours of dark.Įquilux: when day and night are (actually) equalĪstronomical terms & definitions The Equinoxes and the Seasons However, this is literal translation not entirely true. This is the reason it’s called an “equinox,” derived from Latin, meaning “equal night.” In other words, night and day are, in principle, the same length all over the world. On the days of the equinoxes, the Earth’s axis is perpendicular to the Sun’s rays, meaning that all regions on Earth receive about the same number of hours of sunlight. As the Earth travels toward the opposite side of its orbit, which it reaches in December, the Southern Hemisphere gradually receives more sunlight, and the subsolar point travels south.Įarth is tilted as it orbits the Sun, which is why equinoxes and solstices happen. In June, the Northern Hemisphere is tilted toward the Sun, and the subsolar point is north of the equator. ![]() The subsolar point moves north and south during the year because the Earth’s axis is tilted at an angle of about 23.4° in relation to the ecliptic, an imaginary plane created by Earth’s path around the Sun. The December solstice marks the southernmost point of its journey. Having reached its northernmost point at the June solstice, it starts moving southward until it crosses the equator on the day of the September equinox. Sun rise/set and day length around this equinoxĭuring the course of a year, the subsolar point-the spot on the Earth's surface directly beneath the Sun-slowly moves along a north-south axis.This corresponds to Saturday, 23 September 2023, 06:50 UTC. In Odesa, Odessa, Ukraine: Saturday, 23 September 2023, 09:50 EEST (Change location) Business Date to Date (exclude holidays).Whether you’re celebrating spring or autumn, the March equinox represents an interesting moment in our latest journey around the sun. Solstice derives from the Latin solstitium, which literally means “the standing still of the sun.” The solstice occurs around June 21 and December 22. So what about the beginning of summer and winter? Well, the equinox is often confused with the solstice, which is either of the two times a year when the sun is at its greatest distance from the celestial equator. The equinox has inspired a number of interesting false beliefs, including that the event causes a massive disruption of communication satellites, or that on the equinox an egg can effortlessly be balanced on its end (egg balancing is a skill you can practice any day of the year). After all, in the southern hemisphere, March represents the beginning of autumn and spring comes along in September! But if you want to be truly egalitarian, opt for saying March equinox and September equinox instead. The autumnal equinox occurs around September 22nd, when the sun crosses the celestial equator going south. ![]() ![]() In the northern hemisphere, the spring, or vernal equinox happens around March 21, when the sun moves north across the celestial equator. The word equinoxcomes from Latin and means “equality of night and day.” So, the equinox occurs at two specific moments in time when the sun is exactly above the equator (contrary to popular belief, the equinox doesn’t last for 24 hours). But what exactly is the spring equinox? And does an equinox happen at the start of every season?įirst, let’s get into the equinox, which actually occurs just twice a year. We get pretty excited about the spring equinox bringing us out of winter and officially starting the season of spring. ![]()
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