April
Chaul Chhnam - This Cambodian New Year celebration is the equivalent of Songkran in Thailand and follows the end of the harvest season.
Generally lasting for three days from 14-16 April during which time Cambodians douse each other liberally with water, clean and decorate their houses, and make offerings at the local temple.
City streets are decorated and brightly lit in the evenings. There are cultural shows, entertainment, and competitive games.
October
Pchum Ben or Soul Day - Running for 15 days from the end of September into October, and the exact date determined by the lunar calendar, this festival is dedicated to blessing the spirits of the dead, and is one of the most culturally significant in Cambodia. Each household visits their Buddhist temple and offers food to the monks for their assistance in blessing the souls of late ancestors, relatives and friends. Pagodas are crowded with people taking their turn to make offerings, with many staying behind to listen to Buddhist sermons.
Bonn Kathen - A religious festival when monks come out of retreat, and people all over the country form reverent slow processions to their local temple. Monks change their old saffron robes for the new ones offered by the devotees, an action that brings spiritual merit to all participants. Date decided by lunar calendar.
Paris Peace Agreement - October 23rd
Birthday of His Majesty King Norodom Sihanouk - Held over three days from October 30th, people converge from all corners of Cambodia to enjoy the shows, parades, festivals, and a giant firework display in Phnom Penh.
November
Independence Day - A national holiday on November 9th to celebrate the independence of Cambodia from France in 1953. A gala parade is held in front of the Royal Palace, which includes floats, marching bands and other entertaining festive activities.
The Bonn Om Took Water Festival (7-9 November) - Celebrating the reversed current of the Tonle Sap River that connects the Tonle Sap Lake with the Mekong. For most of the year the river flows out from the lake into the Mekong. However, during the rainy season from about June to October the Mekong rises, causing the Tonle Sap River to flow in reverse, and the lake to swell to more than twice its regular size. At the end of the rainy season, when the water level of the Mekong drops again, the current reverts and flows back into the Mekong. This event is celebrated with three days of boat races, fairs, festivals, shows, parades, fireworks, music and dancing.
December
International Half marathon - Held at the world renowned Angkor Wat an event which attracts competitors from all over the world. With thousands of spectators and the wonder of Angkor Wat, it is a spectacular setting.