According to culture of Southeast Fujian province, the 9th day of Chinese New year is the birthday of Jade Emperor, king of heaven and leaders of all Buddhists gods (counterparts of emperor on the Earth)
To celebrate his birthday, people usually offer sacrifices to the Jade Emperor. These sacrifices includes pig, duck, sheep, cake, noodles, fruit. In some areas, there are also dragon or lion dances to celebrate the birthday. People pray to the Emperor at home and then again in the Temper of the Emperor.
There is a legend about how this day comes.
It said during Tang Dynasty, The north army came down to the South during the Chinese New Year. They heard the local people called themselves " wolves" ( In Southeast Fujian dialect, the word "people" in dialect souds like "wolves" in North's people's dialect. Because of this misunderstanding, North army started killing the South People. The South people escaped and hid themselves in the sugar cane fields till the the North army left. The day South People left the sugarcane fields was the 9th day of Chinese New year. The South people prayed to the Heaven God, that's Jade Emperor for salvation during their hideout. People then set this day as the Birthday of Heave god.