What is the holiday custom on April 4th?

The fourth day of the fourth lunar month is the Cold Food Festival, which is one of the traditional festivals in China.

During the Cold Food Festival, people will ban cold food, go hiking to commemorate their ancestors and enjoy the beautiful scenery in spring. The Cold Food Festival is adjacent to Tomb-Sweeping Day and is sometimes regarded as a part of Tomb-Sweeping Day. Tomb-Sweeping Day is around April 4th of the Gregorian calendar every year, which is the "Qingming" solar term in the twenty-four solar terms of the lunar calendar. Tomb-Sweeping Day is an important festival in China. People will visit graves to worship their ancestors, plant trees and fly kites.