The original Roman calendar divided the year from March to December into 10 months of either 29 or 31 days, based on lunar ...

Finally, the calendar we all know was adopted by Pope Gregory XIII in 1582. After skipping 10 days in October 1582 to "catch up," it has changed little since then. What to know about February and ...

A majority of Russian Orthodox churches worldwide use the Julian calendar, which celebrates Christmas on Jan. 7, instead of using the Gregorian calendar proposed by Pope Gregory XIII in 1582.

Council of Florence (1439): DS 1304; Council of Trent (1563): DS 1820; (1547): 1580; see also Benedict XII, Benedictus Deus ... in the age to come. [St. Gregory the Great, Dial.

No living pope had handed off the keys of St. Peter since Gregory XII in 1415. If Pope Benedict had only waited some 14 months to announce his retirement — or abdication, or vacation — we ...

Pope Francis on Sunday called for a unified Easter date among Christian churches in the spirit of promoting unity. "It is a happy coincidence that Easter in this ecumenical Jubilee Year is celebrated ...

A legitimately clutch drive by Lamar Jackson brought the Ravens to a two-point conversion that could have tied the game, but Mark Andrews dropped the ball a la Jackie Smith in Super Bowl XIII.

When a pope dies, or more rarely resigns (Francis's direct predecessor, Benedict XVI, was the first to step down since Gregory XII in 1415), the college of cardinals gathers in the Vatican to ...

Eventually, the calendar we all know was adopted by Pope Gregory XIII in 1582, and it's changed little since then — not that the system is flawless. February gets a leap year once every four ...