Pchum Ben (Khmer:"Ancestors' Day") is a 15-day Cambodian religious festival culminating in celebrations on the 15th day of the tenth month in the Khmer calendar,at the end of the Buddhist lent,Vassa.[1][2] In 2013,the national holiday falls on 03,04,05 October in the Gregorian Calendar.[3]

The day is a time when many Cambodians pay their respects to deceased relatives of up to 7 generation.[4] Monks chant the suttas in Pali language overnight(continuously without sleeping)in prelude to the gates of hell opening an event that is presumed to occur once a year,and is linked to the cosmology of King Yama originating in the Pali Canon .During the periond of the gates of hell opened,ghosts of the dead(preta) are presumed to ne especially active,and thus food-offering are made to benefit them,some of these ghosts having the opportunity to end their period of purgation,where as others are imagined to leave hell temporarily,to then return to endure more suffering,without much explanation,relatives who are not in hell (who are in heaven or otherwise reincarnate) are also generally imagined to benefit from the ceremnies.

In temples adhering to canonical protocol,the offering of food itself is made from the laypeople to the (living)Buddhist monks,thus generating "merit" that indirectly benefits the dead[5]however in many temples this is either accompanied by or superseded by food offerings that are imagined to directly transfer from the living to the dead,such as rice-balls thrown through the air,or rice thrown into an empty field.Anthropologist Satoru Kobayashi observed that these two models of merit-offering to the dead are in competition in rural Cambodia with sosme temples preferring the greater canonicity of the former model,and others embracing the popular(if unorthodox) assumption that mortals can"feed" ghosts with physical food.[6]

Pchum Ben is considered unique to Cambodia,however ,there are merit-transference eremonies that can be closely compared to it in Sri Lanka (ie, benefitting the ghost of the dead )and in its broad outlines,it even resembles the Taiwanese Ghost Festival(i.e,especially in its links to the nation of  a calendrical opening of the gates of hell,King Yama,and so on ).