Editing Roman calendar (section)

===Julian reform===
{{main|Julian calendar}}
[[Julius Caesar]], following his [[Battle of Pharsalia|victory]] in [[Caesar's Civil War|his civil war]] and in his role as ''[[pontifex maximus]]'', ordered a [[Julian reform|reformation of the calendar]] in 46 BC. This was undertaken by a group of scholars apparently including the [[Alexandria]]n [[Sosigenes of Alexandria|Sosigenes]]{{sfnp|Pliny|loc=Book XVIII, Ch. 211}} and the Roman M. Flavius.{{sfn|Macrobius|loc=Book I, Ch. 14, §2}}{{sfnp|Kaster|2011}} Its main lines involved the insertion of ten additional days throughout the calendar and regular intercalation of a single [[leap day]] every fourth year to bring the Roman calendar into close agreement with the solar year. The year 46 BC was the last of the old system and included three intercalary months, the first inserted in February and two more—''{{lang|la|Intercalaris Prior}}'' and ''{{lang|la|Posterior}}''—before the kalends of December.