When and why did the celebration of World Hindi Day start?

Indian communities around the world celebrate World Hindi Day to strengthen their ties to one another and to the language. 

The tenth of January is celebrated as World Hindi Day annually. 

September 14, is also known as Hindi Diwas in India.

It's not always clear when the actual date of Hindi Diwas is. 

the 10th of January is recognised as World Hindi Day, and the 14th of September is recognised as National Hindi Day. 

Both events aim to promote Hindi, but the regional focus of the latter makes it stand out. 

Meanwhile, the date of their respective beginnings is distinct.