With yoga day looming, it's worth considering the politics that lay hidden beyond the ken of most yoga practitioners. This article does a very good job of explaining the issues. This snippet is a good summary:
Firstly, who decided on the date of International Yoga Day? PM Narendra Modi. Why did he choose June 21 every year? Because June 21 is the death anniversary of the first Sarsanghchalak (supreme leader) of the RSS, Keshav Hedgewar, who like other RSS leaders of the time, abstained from the national freedom struggle from 1925 to 1947. What does Hedgewar and the RSS have to do with “India’s ancient cultural heritage”? Isn’t fixing the date for International Yoga Day a political gambit hidden from the people, not only in India?