Beginning of the Common Era

Year 1 is the epoch of the Common Era, a numbering convention fixed centuries later. The count was devised in 525 by the monk Dionysius Exiguus while he was preparing tables for the date of Easter. He numbered years from an estimated year of the Incarnation.

That estimate is a reference point, not a documented date, and most scholars place the birth of Jesus several years earlier, often around 6 to 4 BCE. The epoch fixed the sequence still used for most of the world’s civil dates. The archive marks the year, and does not invent a day for it.