1582 was a common year starting on Monday in the Julian calendar , and a common year starting on Friday in the Proleptic Gregorian calendar . It saw the beginning of the Gregorian calendar switch, the assassination of Oda Nobunaga in Japan, and the Raid of Ruthven in Scotland. Imagine waking up in 1582 and finding that ten days had just disappeared from your calendar . The Gregorian calendar reform of 1582 eliminated ten days from Discover why 10 days went missing in October 1582 and how leap year rules keep our calendar aligned with the Earth’s orbit. The Gregorian calendar as it's known and used today gets its name from Pope Gregory XIII, who oversaw its creation and installment in 1582 . But the road to the implementation of the Gregorian calendar was a rocky one and meant that time had to be sacrificed, one way or another.
