I spotted St Gregory in the window of the church at Welford Park, of Bake Off fame. He is the patron saint of this church. In the window, he is a pope and I assumed he was one responsible for the Gregorian Calendar. I was only 1000 years out. It was a later Gregory who instituted the reform whereby the leap year day is removed on the start year of every fourth century. There was also some correction of dates to get the Spring Equinox back to March 21st. This is all important to get the date of Easter correct. If you're not familiar with that controversy, try Bede's Ecclesiastical History of the English People. It was this first Pope Gregory who sent the missionaries to the Saxons that led to the controversy in the British Isles. The calendar stuff is all because the orbit of the Earth round the Sun is not perfectly a whole number of rotations of the Earth.
