Thursday, November 18
"These fears were focused in 1582, when the vigorous reforming Pope Gregory XIII revised the existing hopelessly innacurate 'Julian' Calendar, omitting ten days from October 1582 to correct the errors which had crept in over the centuries, and introducing a new method of calculating the Leap Years to prevent new innacuracies from arising. Gregory's reform was long overdue: the need for a reform had been widely discussed for centuries, and it was a huge improvement over the existing calendar. It was widely welcomed by astronomers and scientists, including the Protestants Johann Kepler and Tycho Brahe. The Gregorian Calendar, however, caused widespread anger and fear among Protestants, many of whom saw it as a device of Antichrist to subject the world to the devil. Gregory's coat of arms included a dragon, and this was seized upon [...] as an omen. The Pope, it was claimed, was trying to confuse calculations of the imminent end of the world, so that Christians would be caught unprepared. The changes were an interference with the divine management of the universe. [...] Gregory was attempting to smuggle idolatrous observances into the world under the pretext of more efficient calculation. The university of Tubingen declared that anyone who accepted the new Calendar was reconciling themselves to Antichrist. It was outlawed in Denmark, Holland, and the Protestant cantons of Switzerland, and in many German Protestant states the civil authorities prevented the Catholic clergy from using it. [...] England did not accept the new calendar until 1752, and Sweden not until 1753. The Pope had become the bogey-man of Protestant Europe."
--Eamonn Duffy, Saints and Sinners: A History of the Popes, pp. 180-181.
Incidentally, I have seen Gregory XIII's tomb in St. Peter's, with its wonderful sculpted baby dragon peering up out of a stone coffin. He's the cuddliest, most harmless thing you'll ever see...