September Equinox 2026 शरद विषुव

Why September Equinox is celebrated

The September equinox is an astronomical event, not a festival or holiday. It marks the point in Earth's orbit when the Sun appears directly above the equator. After this moment, the Sun moves into the southern half of the sky, and the Northern Hemisphere, including India, begins its slow move towards shorter days and cooler nights. In the Southern Hemisphere, it marks the start of spring.

History and story of September Equinox

Earth's axis is tilted by about 23.5 degrees. As Earth travels around the Sun, this tilt changes how directly sunlight falls on each hemisphere, giving us seasons. Twice a year, in March and September, the tilt is sideways to the Sun, and both hemispheres receive nearly equal light. Indian astronomers called these points vishuva.

In 2026, the equinox occurs at 00:05 UTC on 23 September, which is 5:35 am Indian Standard Time.

How September Equinox is celebrated

On the equinox, day and night are close to twelve hours each across India. Because sunlight bends in the atmosphere and the Sun's whole disc is counted, the day is in fact a few minutes longer than twelve hours. Exactly equal day and night come a few days later in Indian cities. After this, days keep getting shorter until the December solstice.

The equinox also has an honest link with Indian calendars. In the Indian National Calendar, the month of Asvina begins on 23 September. The traditional Hindu calendar uses the sidereal zodiac, so the Sun enters Tula, or Libra, only around mid October. Pitru Paksha and Sharad Navratri usually fall in the weeks around and after the September equinox, as the monsoon ends and the clear autumn season, called Sharad ritu, begins.