When did Tomb-Sweeping Day come?

Qingming was just the name of a solar term at first, and later became a festival to commemorate ancestors, which was related to the Cold Food Festival. Jin Wengong designated the second day of the Cold Food Festival as Tomb-Sweeping Day. The Cold Food Festival was set up to commemorate the Jiexiu, a loyal minister of the State of Jin. The Cold Food Festival was changed to Tomb-Sweeping Day because of a poem left by Jiexiu before his death:

I hope your master is always clear.

It is better to be a ghost than to accompany you as an exhorter.

If your master has me in his heart, remember that I often reflect.

I have a clear conscience in Jiuquan, diligent and honest.

The next year, when Jin Wengong offered a sacrifice to Jietui, he designated this day as Tomb-Sweeping Day.

The traditional Tomb-Sweeping Day in China began in the Zhou Dynasty and has a history of more than 2,500 years. Qingming is first and foremost a very important solar term. As soon as Qingming arrives, the temperature rises, which is a good time for spring ploughing and sowing. Therefore, there is an agricultural proverb "Before and after Qingming, plant melons and beans" and "Planting trees is not as good as Qingming".