Asteroid named after pope behind Gregorian calendar reform ROME (AP) — Pope Gregory XIII, the 16th century pontiff responsible for the Gregorian calendar, now has another celestial claim to fame.

The Gregorian calendar, instituted by Pope Gregory XIII, went into effect in 1582. In the 1,417 years from 1583 through 3000, it’s most common for Easter to fall on April 16, with 61 instances.

Faith News New asteroids named for 3 Jesuits and pope of ‘Gregorian calendar’ fame Carol Glatz - Catholic News Service March 01, 2023 ...

The sun sets behind the dome of St. Peter’s Basilica, in Rome, on Feb. 20, 2023. Pope Gregory XIII, the 16th century pontiff responsible for what is today known as the Gregorian calendar, now ...