Day and Night to Become Nearly Equal in Pakistan on September 23

Pakistan, along with many parts of the world, will experience nearly equal lengths of day and night on September 23 as the Sun crosses the equator while moving from the Northern Hemisphere toward the Southern Hemisphere.

The astronomical event is known as the September Equinox, or autumnal equinox in the Northern Hemisphere. In 2026, the equinox will occur at around 5:05 am Pakistan Standard Time on September 23.

Why Do Day and Night Become Nearly Equal?

Earth is tilted on its axis by about 23.5 degrees. Because of this tilt, the Northern and Southern hemispheres receive different amounts of sunlight during different parts of the year.

During an equinox, however, the Sun is positioned directly above the equator. As a result, both hemispheres receive almost equal amounts of daylight, bringing the duration of day and night close to 12 hours each across much of the world.

Although the event is commonly described as having exactly 12 hours of daylight and 12 hours of darkness, the actual duration varies slightly due to atmospheric refraction and the way sunrise and sunset are measured.

What Does the September Equinox Mean for Pakistan?

The September Equinox marks the astronomical beginning of autumn in the Northern Hemisphere, where Pakistan is located.

Following the equinox, daylight hours in Pakistan will gradually become shorter while nights will continue to grow longer.

The change will become increasingly noticeable during the final weeks of September and throughout the following months, continuing until December when the Northern Hemisphere reaches its shortest day of the year.

Spring Begins in the Southern Hemisphere

While Pakistan and other countries in the Northern Hemisphere enter astronomical autumn, the September Equinox marks the beginning of spring in Australia, New Zealand and other parts of the Southern Hemisphere.

Two equinoxes occur each year. The first takes place in March when the Sun crosses the equator from south to north, while the second occurs in September as the Sun moves from the Northern Hemisphere toward the Southern Hemisphere.

The September Equinox is therefore an important point in Earth's annual journey around the Sun, marking a seasonal transition across both hemispheres.