BY the 16th century, scholars had realized that the Roman Empire’s Julian calendar was out of sync with the solar year — and that Easter was falling further away from the spring equinox.
In an effort to close the gap, Pope Gregory XIII introduced the Gregorian calendar. But because of old religious rivalries, Protestants in Europe were dead set against the change. It wasn’t until 1752 that
England adopted the Gregorian calendar. On that day, the country skipped forward 11 days overnight, going from Wednesday, September 2, to Thursday, September 14. The Gregorian calendar is still the most widely used civil calendar today.
Eastern Orthodox churches still use the Julian calendar to calculate religious holidays. As a result, while most of the Western world will celebrate Easter on April 5 this year, Orthodox churches are celebrating on April 12.