The year in which it occurred was termed annus bissextus, in English the bissextile year.
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In a leap year, February 29, the bissextile day, does not have a distinct letter.
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Mar., so if the days were numbered from the beginning of the month, it was named February 24 in common years, but the presence of the bissextum in a bissextile year immediately before a. d. VI Kal.
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He argued that Caesar would have enforced the bissextile day by introducing it in his first reformed year.
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The Alexandrian calendar adapted the Egyptian calendar by adding a 6th epagomenal day as the last day of the year in every fourth year, falling on the 29 August preceding a bissextile day.