Most of the fairs and festivals in Kathmandu originated in the Malla period or earlier. Traditionally, these festivals were celebrated by Newars. In recent years, these festivals have found wider participation from other Kathmanduites as well. As the capital of the Republic of Nepal, various national festivals are celebrated in Kathmandu. With mass migration to the city, the cultures of Khas from the west, Kirats from the east, Bon/Tibetan from the north, and Mithila from the south meet in the capital and mingle harmoniously. The festivities such as the Ghode (horse) Jatra, Indra Jatra, Dashain Durga Puja festivals, Shivratri and many more are observed by all Hindu and Buddhist communities of Kathmandu with devotional fervor and enthusiasm. Social regulation in the codes enacted incorporate Hindu traditions and ethics. These were followed by the Shah kings and previous kings, as devout Hindus and protectors of Buddhist religion.

To what era do a majority of Kathmandu's festivals date back to?