In the wake of the runaway success of his ‘Happy’ single, Pharrell Williams is working with the United Nations Foundation to celebrate the International Day of Happiness.

The International Day of Happiness will take place on March 20.

Originally established in 2012 by the United Nations General Assembly, the International Day of Happiness acknowledges that "the pursuit of happiness is a fundamental human goal" and "the need for a more inclusive, equitable and balanced approach to economic growth that promotes sustainable development, poverty eradication, happiness and the well-being of all peoples.”

Starting this Monday (March 10) people are encouraged to post videos of themselves on YouTube and Pharrell Williams’ ’24 Hours of Happiness’ website showing them “demonstrating their happiness” to his million-selling song.

Videos should be accomanpied by the hashtag #HAPPYDAY.

On March 20, Pharrell Williams will select the best video submissions at noon in each time zone.

Pharrell Williams is expected to achieve his first No. 1 UK album tomorrow (March 9) with his new LP ‘G I R L’.

Watch Pharrell Williams performing 'Happy' at the Oscars below: