Autumnal equinox approaches: nights begin to lengthen from September 23

An important astronomical shift is occurring in nature: on September 23, the Sun crosses the celestial equator, marking the beginning of astronomical autumn in the Northern Hemisphere. From then on, days will shorten and nights will gradually lengthen.

Many believe September 22 is the "day of equal day and night." However, in 2026, the autumnal equinox in Tashkent time will occur on September 23 at 05:05 at this exact moment, the center of the Sun crosses the plane of the Earth's equator.

What does "Equinox" mean?

The term "Equinox" comes from the Latin aequus — meaning "equal" and nox — meaning "night."

The equinox occurs twice a year — in March and September. In March, it marks spring in the Northern Hemisphere, and in September, the autumnal equinox.

During the autumnal equinox, the Sun crosses the celestial equator from north to south. Afterward, in the Northern Hemisphere, the Sun follows a lower trajectory across the sky each day, and the duration of daylight decreases.

Why are day and night not exactly 12 hours long?

The term "equinox" does not mean that day and night are exactly 12 hours long.

In reality, due to atmospheric refraction and the fact that sunrise and sunset are calculated based on the top edge of the Sun's disk rather than its center, daylight lasts slightly longer than 12 hours in most places.

For example, on September 22 in Tashkent, daylight lasts approximately 12 hours and 11 minutes. From September 23, the duration of the day begins to shorten again.

What changes from tomorrow?

After the autumnal equinox, days in the Northern Hemisphere continue to shorten, and nights continue to lengthen.

In Tashkent, on September 22, the Sun rises at approximately 06:10 and sets at 18:20. On September 23, the duration of daylight drops to approximately 12 hours and 8 minutes. In the following days, this difference will continue to increase.

This process continues until the winter solstice in December. After that, the days will gradually begin to lengthen again.

The astronomical beginning of a major change in nature

The equinox is not just a date on the calendar. It is an important astronomical event related to the Earth's movement around the Sun and the tilt of our planet's axis.

Therefore, September 23, 2026, is considered the starting point of astronomical autumn for the Northern Hemisphere. is considered.

So, today is the eve of the equinox. From early tomorrow, another familiar law of nature will manifest: days will shorten, and nights will begin to lengthen.