Gas storage characteristics of cold food

The Cold Food Festival, also known as "No-smoking Festival", "Cold Food Festival" and "Hundred Five Days Festival", is one hundred and five days after the summer calendar and one or two days before Tomb-Sweeping Day. When the first day of the day is a holiday, smoking is forbidden and only cold food is eaten. In the development of later generations, the customs of sweeping, climbing, swinging, cuju, crochet and cockfighting were gradually increased. The Cold Food Festival lasted for more than 2,000 years and was once called the largest folk festival. Cold Food Festival is the only traditional festival of Han nationality named after food customs. Later, because cold food was close to Qingming, people combined cold food with Qingming before crossing Tomb-Sweeping Day.

The Cold Food Festival is usually from winter to the day after 105. The days near Tomb-Sweeping Day. Before the calendar reform in Tang Ruowang in the early Qing Dynasty, Tomb-Sweeping Day was scheduled for two days after the Cold Food Festival. After the reform of the Tang family, the Cold Food Festival was held the day before Tomb-Sweeping Day. The definition of modern twenty-four solar terms follows the Tang family, so the Cold Food Festival is the day before Tomb-Sweeping Day. After the founding of New China, many regions equated the Cold Food Festival with Tomb-Sweeping Day and celebrated it on the same day.

However, in most parts of Shanxi, the day before Tomb-Sweeping Day was the Cold Food Festival. Some places, such as Yushe County, celebrated the Cold Food Festival two days before Tomb-Sweeping Day. Yuanqu County also pays attention to Tomb-Sweeping Day's Cold Food Festival the day before, and the light cold food the day before.

The source of the Cold Food Festival should be the worship of fire by ancient humans. The ancients could not live without fire, but fire often brought great disasters to mankind, so the ancients thought that fire was a god and should be worshipped. The fire offered by each family must be extinguished once a year. Then rekindle a new fire, which is called changing the fire. When changing the fire, a grand ancestor worship activity should be held, and the symbol of millet, the god of cereal, should be burned, which is called human sacrifice. After the custom was passed down, it formed the later No Fire Festival.