The first ever International Yoga Day was celebrated last June 21, 2015. The specific date was suggested by India's Prime Minister, Narendra Modi. The 21^st coincided with the longest day of the year, also known as the Summer Solstice, and holds a special meaning from the perspective of yoga.

The Prime Minister is a known yoga enthusiast and surprised everyone when he joined over 35,000 people for a yoga demonstration at Rajpath. Speaking to the participants, Modi told them that they were not just "celebrating a day" but they are also "training the human mind to begin a new era of peace and harmony."

He also acknowledged the United Nations and the 177 countries that helped made International Yoga Day a reality.

Modi, who was wearing white with a national tricolor scarf, also said that the day was also "programmed for human welfare, a tension-free world and a program to spread the message of love, peace and goodwill."

 The 64-year-old then joined the participants in going through most of the 21 "asanas" or poses.

The day was also observed in more than 251 cities in 191 countries. Indian diplomats and missions in the various countries organized events to celebrate the day and most were successful. And like in India, thousands of yoga enthusiasts took to their mats and held yoga demonstrations.

In the US, people sat on bright red mats in Time Square and did yoga in the early morning hour. A demonstration was also held across the White House, with participants wearing white shirts bearing the hashtag #YogaDay2015.

One country with millions of yoga practitioners is China, and thousands of them came together to celebrate the day in events organized by the local government and a few yoga institutes. According to the Indian Embassy, events were held in Beijing, Shanghai, Hong Kong, Macau, Xiamen, Guangzhou and Changzhou.

 The United Kingdom and Paris also joined in the celebrations, with yoga practitioners doing a few asanas on the bank of the river Thames and under the Eiffel Tower.

Other countries that participated were Afghanistan, Australia, Nepal, Pakistan, Singapore, South Africa and Thailand.