EVENTS and FESTIVALS
Cambodia has a richness of traditional and international festivals. The majority among those is a time of great rejoicing for the mainly rural population, which flows to the capital to join the celebrations and to be pilot organized exposures of fireworks, which accompany the festivals. All the traditional festivals are under the influence of Buddhism, Hinduism and the royal cultures.

Most important celebrations organized during the year.
Water festival (October or November)
Pchum Ben (September)
the celebration of Birthday of King Sihanouk (on October 31)
. Khmer New Year's Day (mid-April)
Angkor Festival (November or December): This festival is a window of arts executants with Angkor Wat like a bottom. The interpreters of everywhere Asia follow this festival carrying out of the great epic stories of myths and the legends, including Ramayana, with their own national costumes of dance and of musical and rhythmic interpretations.
Day of the ploughings of the king (May)
Day of Independence (on November 9)
New Chinese Year (January or February): because of the many people of Chinese descent who direct much companies to Kampuchea; and also of the communities of emigrant Vietnamese's, Chinese New Year's day is largely celebrated, particularly in Phnom Penh.
The national festival (on January 7): One of the festivals most recent, this day marks the end of the Khmer Rouge Mode.

Useful resources:

BBC - Holiday - Destinations

Vietnam Holidays. Guide to Lastminute Holidays in Vietnam