Republic Day is a national holiday in India, when the country marks and celebrates the date on which the Constitution of India came into effect on 26, January 1950, replacing the Government of India Act (1935) as the governing document of India and thus, turning the nation into a newly formed republic. The day also marks the transition of India from an autonomous Commonwealth realm with British Monarch as nominal head of the Indian Dominion, to a fully sovereign Commonwealth republic with the President of India as the nominal head of the Indian Union.