National Democracy Day, celebrates the 1951 overthrow of the Rana dynasty (Nepal)

Nepal uses three official calendar systems, including the Nepal Sambat as the main and national calendar, the Vikram Samvat for Hindu holidays, and the Gregorian calendar for international events and holidays.

The Rana dynasty was a Chhetri dynasty that imposed authoritarianism in the Kingdom of Nepal from 1846 until 1951, reducing the Shah monarch to a figurehead and making the Prime Minister and other government positions held by the Ranas hereditary. The Rana dynasty is historically known for their iron-fisted rule in Nepal. This changed after the Revolution of 1951 with the promulgation of a new constitution, when power shifted back to the monarchy of King Tribhuvan.

Nepal, officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia. It is mainly situated in the Himalayas, but also includes parts of the Indo-Gangetic Plain. It borders the Tibet Autonomous Region of China to the north, and India to the south, east, and west, while it is narrowly separated from Bangladesh by the Siliguri Corridor, and from Bhutan by the Indian state of Sikkim. Nepal has a diverse geography, including fertile plains, subalpine forested hills, and eight of the world's ten tallest mountains, including Mount Everest, the highest point on Earth. Kathmandu is the nation's capital and its largest city. Nepal is a multi-ethnic, multi-lingual, multi-religious, and multi-cultural state, with Nepali as the official language.