Autumnal equinox is one of the 24 solar terms of the Chinese lunar calendar.

It usually falls between Sept. 22 and 24, during the country's harvest season.

This year, the autumnal equinox falls on Sept. 23.

In 2018, China designated this day for farmers to celebrate the annual harvest, the first festival created by the state specifically for the country's farmers.

The 24 solar terms were created thousands of years ago by the ancient Chinese to guide agricultural production.