This year, the spring equinox for the Northern Hemisphere will take place on March 20, 2021. Finally, after months of cold weather and hours of darkness, the sun will become more and more prominent through the day. For centuries, the vernal equinox has been a time of celebrating renewal and rebirth for many civilizations. But aside from marking the beginning of spring, what does the equinox signify?
During the course of Earth’s rotation around the sun, there are four distinct positions that indicate we're heading into a new season. Scientifically, they’re known as equinoxes (vernal in the spring and autumnal in the fall) and solstices (which happen in the summer and winter).
Equinox vs. Solstice
Like the seasons they represent, solstices are times of extremes. The summer solstice occurs when the Sun is at the highest point in the sky, and thus marks the longest day of sunlight of the year. The winter solstice is the opposite — when the Sun is at its lowest point and is accompanied by the shortest day of the year.
Directly between the two solstices are the equinoxes, which are considered times of equality (equinox is derived from the Latin words for "equal" and "night"). These are the two times of the year where day and night have equal lengths. On the equinox, the Sun passes over the equator at noon.
The spring equinox is the day when the sun crosses the celestial equator and days and nights share an equal length. From that point on, the hours of sunlight will be longer than the hours of darkness until the fall equinox. Then, at the autumnal equinox, the sun will cross the equator again, and the following days will become shorter than the nights.
While Americans and others in the Northern Hemisphere refer to the equinoxes as spring and autumn, that could lead to some confusion for people in other parts of the world. When the Northern Hemisphere experiences the spring equinox in late March, people in the Southern Hemisphere are entering into autumn. For those living in the Southern Hemisphere, the equinox that occurs in late September brings on the spring season.
After months of shortened daylight hours and, historically, a time when food and other supplies could run low if you weren't properly prepared for a long winter, it’s only natural that people would want to celebrate the end of a season of hardship and the beginning of a season of growth.
For most Christians, the spring equinox is used to determine the date for Easter, a holiday centered around resurrection (it's the first Sunday after the first full moon following the vernal equinox). Jewish families celebrate Passover, which symbolizes a time of new beginnings, based on a lunar calendar as well.
The Chinese are said to have started the ancient tradition of balancing eggs on the spring equinox. Eggs represent fertility, and if you can manage to balance your egg upright on the day of rebirth and renewal, it's said you'll experience good luck and prosperity in the year to come.
The spring equinox is also the start of the new year based on some ancient astrological calendars. Many cultures of Persian and Zoroastrian decent, such as Iranians, hold long, multi-day celebrations to ring in Nowruz (new year) at this time.
But no matter how you choose to celebrate, the promise of increasing hours of sunlight is more than enough reason to look forward to the vernal equinox.