Top Theories on What's Going On With North Korea's Kim Jong Un.

(Bloomberg) -- The Day of the Sun -- the April 15 holiday celebrating Kim Jong Un's late grandfather, Kim Il Sung -- has long been the most important date on North Korea's political calendar. The Daily NK, a Seoul-based news outlet that gathers information from people inside North Korea, reported April 20 that Kim underwent a "cardiovascular surgical procedure" the previous week and was now mostly recovered. [Extracted from the article]