Siddhartha Gautama, whom the vulgar are wont to name "the Buddha" (as if there were only one), was born Hindu. The concepts of a personal deity and a reincarnated soul bothered him and the longer he meditated upon them the sooner he understood emptiness. William Butler Yeats was familiar with Hindu cycles of time; after all, he was an initiate of England's then-leading occult fraternal order,the Order of the Golden Dawn. He had contact with Aleister Crowley who was greatly influenced by another member of the Order, a Theravadan Crowley probably loved. The Hindu concept of time is cyclical, and Yeats had the Kali Yuga in mind when he wrote "The Second Coming."
If memory serves me correctly, the major explication of the Hindu cycles of time is in the Shiva Purana. It has all the features of the world today, a kind of Oriental version of the debatably eschatological Revelations of John of Patmos. The gospel was written using isopsephia to send a coded message: The Great Beast = Nero Caesar. Some might argue that it doesn't take a belief in God for the End Times to be coming. At least with the Hindu version, though, we have our afterlife on earth, with a new Golden Age, not one in "heaven" or "paradise," whether we're met by angels or virgins. Or raisins. The lines:
The best lack all conviction, while the worst
Are full of passionate intensity
perfectly decribe the foolishness in the capital and the presence of people like Antonin Scalia on the Supreme Court.
Yeats was a fine poet, but some of his works are reflections of the knowledge and, indeed, wisdom he acquired during his occult period.