The festival held for nine days. During that time devotees and the medium must stay on no blood meal(a fully strict vegetarian diet) and no sexual intercourse. And if I not mistaken women are in menstrual period also forbid to pray.
The Nine Emperor Gods are part of a spirit-medium cult known locally as Jieu Hwang Yeh. These nine deities are believed to dwell in the stars in heaven under the reign of Mazu.
On the eve of the ninth moon, temples of the deities hold a ceremony to invoke and welcome the nine emperors. Since the arrival of the gods are believed to be through the waterways, processions are held from temples to the sea-shore or river to symbolize this belief. Devotees dressed in traditional white, carrying incense and candles, await the arrival of their excellencies.
A carnival-like atmosphere pervades the temple throughout the nine-day festival. During this period of time, the constant tinkling of a prayer bell and chants from the temple priests are heard. Most devotees stay at the temple, eat vegetarian meals and recite continuous chanting of prayer. It is believed that there will be rain throughout the nine days of celebration.
The ninth day of the festival is its climax. A procession which draws scores of devotees send the deities back home (a waterway such as river or sea).
The last days of this festival always be mystery to me. It always drizzle in last days of this festival.