Gregory Calendar. Because this is the calendar that we use day in and out — we felt that we would be remiss if you didn’t know the following 18 gregorian calendar facts. It was first used in 1582, as an evolution of what already existed, enabling people to understand the year and season with.
The calendar we use today, known as the gregorian calendar, was commissioned by pope gregory xiii in the 16th century. It was instituted by papal bull inter gravissimas dated 24 february 1582 by pope gregory xiii, [3] after whom the calendar is.