This ceremony is an offering to the Ancestors' Spirits. It is a tradition that this time of the year those spirits are believed to have released from the "plain of hell" to receive offerings. It is followed by Boun Haw Khao Salark, 15 days later, which is the day when offerings are made to the Ancestors' spirit on their last day before returning to the afterlife and the day they can take the offerings and prayers with them.