Phcum Ben ? Day of Feeding Spirits ? Mid or End of September: Widely celebrated across the country, usually from the end of September into October. It is a special and unique festival to Cambodia. Running for 15 days, people pay respect to their ancestors, spend time with their families and make offerings in their local temples.ABBA Bodybuilding Competition ? Toward Second Week of September: The event will feature athletes from Siem Reap and Phnom Penh as well as major cities in Cambodia. Angkor Bodybuilding Association (ABBA) organizes the event with the support of Cambodia Federation of Bodybuilding as well as generous, local businesses, sport fans and supporters.