This festival take place on 5th day of the fifth lunar month in every house of the Kinh (Viet).
This is the middle year festival for the prevention of disease and ward off evil spirits (the day of changing weather from spring to summer, this is the time easy to get pathogen). On the day of “killing inner insects”, every one has to get up early, eat fermented sticky and fruits. The worshiping is held at noon, hour of Ngo.