 The former began somewhere in the 4th century, as evidenced by Ethiopic copies of Alexandrian tables covering three lunar cycles from 310/11 to 367/68.The dates are secured by the inclusion of an indiction column, and the included Easter dates are consistent with the later dates of Dionysius Exiguus and Bede.The classical Alexandrian 19-year lunar cycle itself or a close variant of it was added to the festal letters of Athanasius during the late 4th century; it was used by Annianus in his 532-year tables during the early 5th century, was fully enumerated in the subsequent 532-year Ethiopic tables, and was adopted by bishop Cyril of Alexandria (without any mention of a 532-year table).