India to experience equal day and night today: What changes from Thursday?

The Sun crosses Earth's equatorial plane today, marking the September equinox. Here's what the astronomical event means for India's daylight and seasons.Children play cricket with a setting sun in the background, illustrating the September equinox. (Photo: PTI)The Sun will cross a key astronomical boundary today, September 23, marking the September or fall equinox, an event that signals the changing of seasons across the Northern Hemisphere.In India, the equinox will occur at 5:35 am IST, according to Nasa's astronomical calculations.At that precise moment, the centre of the Sun crosses Earth's equatorial plane, moving from north to south.But what does that actually mean for the people in India? As of Sept. 22, it's officially fall in the Northern Hemispherewhile spring begins in the Southern Hemisphere.That's the September equinox, when the Sun is directly above Earth's equator and day and night are close to equal in length around the world. pic.twitter.com/hugAKJ539t— NASA JPL (@NASAJPL) September 22, 2026 WHAT IS AN EQUINOX?An equinox happens twice a year, once in March and once in September.The word comes from Latin for “equal night”, referring to the near-balance between daylight and darkness. The event happens because Earth's axis is tilted by about 23.5 degrees as the planet travels around the Sun. During an equinox, neither hemisphere is tilted towards the Sun, allowing sunlight to fall more evenly across the two halves of Earth.The March equinox marks the beginning of astronomical spring in the Northern Hemisphere, while the September equinox marks the beginning of astronomical autumn, or fall.Fall arrives today at 8:05 pm ET!Today’s Fall Equinox marks the start of astronomical fall in the Northern Hemisphere and is the moment when the Sun is directly over Earth’s equator. From now through the Winter Solstice on December 21, the Northern Hemisphere will receive pic.twitter.com/Z5UsEYzSts— National Weather Service (@NWS) September 22, 2026WILL DAY AND NIGHT BE EQUAL?Despite its name, the equinox does not mean every location will experience exactly 12 hours of daylight and 12 hours of darkness.Earth's atmosphere bends sunlight, while the way sunrise and sunset are defined also affects the calculation. As a result, daylight generally lasts slightly longer than 12 hours around the equinox.What does change is the trend. The sun rises above the Pyramid of the Sun, as people celebrate the Spring Equinox, in Mexico. (Photo: AP) After the September equinox, the Northern Hemisphere begins receiving progressively less direct sunlight as Earth's position changes.In other words, from today onwards, the days will gradually become shorter and nights will grow longer, leading towards the December winter solstice.WILL EQUINOX AFFECT INDIA TOO?The equinox is an astronomical turning point, but it does not mean India abruptly enters an autumn-like season.India's weather is strongly shaped by the monsoon, geography and regional climate. So the change in daylight will be gradual rather than producing an immediate nationwide shift in temperature or weather. An illustration showing the two Equinox through a year. (Photo: Nasa) Still, the equinox marks an important transition in Earth's annual cycle.It explains why daylight hours begin shrinking across India in the months ahead, a change that will continue until the December solstice, when the Northern Hemisphere reaches its shortest day and longest night.- EndsPublished On: Sep 23, 2026 16:11 IST