Date(s) - 23/10/2017
October 23 is celebrated as a public holiday in Cambodia, commemorating the 1991 Paris Peace Agreements that ended decades of conflict in the country. Specifically, it ended the Cambodian-Vietnamese War that had begun back in 1979, but the nation had been in a state of turmoil since 1975, when the genocidal Khmer Rouge regime had seized control of the government. Source.
If October 23 falls on a Saturday or Sunday, a public holiday is observed on the following Monday.