The traditional Chinese solar calendar divides a year into 24 solar terms. The Spring Equinox (Chinese: 春分), as the fourth term of the year starts on March 21 and ends on April 4 this year.

The Spring Equinox signals the equal length of the day and night time. On the day of the Spring Equinox, sun is directly above the equator. After the equinox, the sun moves northwards, resulting in gradually longer day time in the Northern Hemisphere and longer night in the Southern Hemisphere.

Here are things you may not know about the Spring Equinox.

Swallows fly north

The ancient Chinese people divided the fifteen days of the Spring Equinox into three "hou's," or five-day parts. As the old saying goes, swallows fly back to the North in the first hou; thunder cracks the sky in the second hou; lightning occurs frequently in the third hou, which vividly reveals the climate feature during the Spring Equinox.

Egg-standing games

Standing an egg upright is a popular game across the country during the Spring Equinox. It is an old custom that dates back to 4,000 years ago. People practice this tradition to celebrate the coming of spring. It is believed that if someone can make the egg stand, he will have good luck in the future.

Some believe that the Spring Equinox is the best time to practice this game because on this day the axis of the earth is relatively balanced against the orbital plane of the earth's rotation around the sun, which makes it easier to erect an egg.

Flying kites

Spring Equinox is a good time to fly kites. In ancient times, people did not have good medical resources. So to pray for health, they wrote their medical issues on paper kite. When the kite was in the air, people would cut off the string to let the paper kite float away, symbolizing the flying away of diseases.

Later flying kites developed into a popular game of spring. On the Spring Equinox, people write a blessing on the kite, hoping that the gods in the sky would see it.

Eating spring vegetables

Eating spring vegetables during the Spring Equinox is a commonly practiced custom in many regions of China. 'Spring vegetables' refers to seasonal vegetables that differ from place to place. The ancient teachings in the Chinese classic,Huangdi Neijing, suggests that people eat seasonal foods to help preserve health and bring good luck.

Reward farm cattle

This practice is popular in the southern area of the lower reaches of the Yangtze River. As the Spring Equinox comes, farm work starts and both the farmers and the cattle start to become busy. Farmers will reward cattle with sticky rice balls to express their gratefulness. Meanwhile, people will also make sacrifice to birds, to thank them for bringing signals for farm work and to ask them not to eat grains later in the year.