Firstly, the Han Chinese had the habit of sacrificing ancestors in the month of Laha in ancient times, and "Shuowen" recorded that "Laha sacrifices to all the gods on the day of the third eleventh day after the winter solstice." To the North and South Dynasties when this date in the Buddhist Buddha became the day of the combination, identified as the eighth day of the waxing moon.
Secondly, according to Buddhist legend, the eighth day of the first lunar month is the day of the Buddha's enlightenment, before the Buddha's enlightenment, he had received the shepherdess's milk porridge to restore his strength, and then under the Bodhi Tree after 49 days of contemplation, on the eighth day of the first lunar month, he saw the morning star and realized the truth. Therefore, Buddhists celebrate the Buddha's enlightenment on the eighth day of the first month of the Lunar New Year.