Why is Hindi Diwas celebrated?

September 14th, is celebrated as Hindi Day because on this day in 1949, the Constituent Assembly of India had adopted Hindi written in Devnagari script as the Official Language of the Union.

Hindi Diwas is celebrated all through the India to show the importance of Hindi language in the country. The Hindi language in India has a long history, and it is the language spoken as a mother tongue by around 258 million people, and known as the 5th largest language of the world.