On which day of the lunar calendar is the Jade Emperor's birthday celebrated?

The Jade Emperor's birthday is celebrated on the ninth day of the first month of the lunar calendar.

Known in Chinese as Tiangong Dan or the Heavenly God’s Birthday, the festival honors the Jade Emperor as the supreme heavenly administrator in many Taoist and Chinese folk-religious traditions. The date falls during the Lunar New Year period, when families and temples perform rituals for blessing, protection, health, and prosperity.

Celebrations commonly begin late on the eighth lunar day and continue into the ninth. Worshippers may erect a high altar, burn incense, offer fruit, cakes, tea, wine, and vegetarian foods, and perform ceremonial bows. In Taiwan and southern Chinese communities, the observance is especially prominent and is often called bai Tiangong, or “worshipping Heaven.”

The festival should not be confused with the birthdays of other important figures, such as Guanyin’s observances or the Buddha’s Birthday on the eighth day of the fourth lunar month. Because the holiday follows the lunar calendar, its date on the Gregorian calendar changes every year.