Our calendar is a 400-year calendar, requiring that period to complete its leap-year cycle. I thought it was quite curious that 2020 marked the 400th anniversary of the introduction of scientific method (Francis Bacon's Novum Organum), as well as the 400th anniversary of the introduction of democratic governance in the North American colonies. Both were revolutions from top-down to bottom-up methods.
Having heard Terry Wolfe's reading of Revelation, in which he assigns the Four Horsemen to Constantine (the pope in white), Charlemagne (the cardinals in red), the Jesuits (black), and the Green Movement currently underway, I saw a similar 400-year pattern. This is really interesting, and I'll be writing more about it, but I thought I'd throw that out. Additionally, around 1200 AD, the third 400-year iteration, you had the suppression of the Templars, who went and founded Switzerland afterward. It's really curious.