Bede (c.672–735) was the first historian to use a BC year, and hence the first to adopt the convention of no year 0 between the BC and AD epochs, in his Historia ecclesiastica gentis Anglorum (Ecclesiastical history of the English people, 731). Previous Christian histories used anno mundi ("in the year of the world"), or anno Adami ("in the year of Adam", beginning five days later, used by Africanus), or anno Abrahami ("in the year of Abraham", beginning 3,412 years later according to the Septuagint, used by Eusebius), all of which assigned "one" to the year beginning at Creation, or the creation of Adam, or the birth of Abraham, respectively. All began with year 1 because the counting numbers begin with one, not zero
. Bede simply continued this earlier tradition relative to the AD era. Bede continued to use this zero epact in his De temporum ratione (On the reckoning of time, 725), but did not use it between dates BC and AD. .......
Bede did not sequentially number any other calendar units (days of the month, weeks of the year, or months of the year — but he was aware of the Jewish days of the week which were numbered beginning with one (except for the seventh which was called the Sabbath) and partially numbered the days of his Christian week accordingly (Lord's day, second day, …, sixth day, Sabbath in English translation).
In chapter II of book I of Ecclesiastical history, Bede stated that Julius Caesar invaded Britain "in the year 693 after the building of Rome, but the sixtieth year before the incarnation of our Lord", while stating in chapter III, "in the year of Rome 798, Claudius" also invaded Britain and "within a very few days … concluded the war in … the fortysixth [year] from the incarnation of our Lord". Although both dates are wrong, they are sufficient to conclude that Bede did not include a year zero between BC and AD: 798 − 693 + 1 (because the years are inclusive) = 106, but 60 + 46 = 106, which leaves no room for a year zero