Letters to Quintus and Brutus. Letter Fragments. Letter to Octavian. Invectives. Handbook of Electioneering,
LCL 462: 447
Until Julius Caesar reformed the calendar the Roman year consisted of 355 days divided into twelve months, all of which bore the Latin forms of their present names except Quintilis (July) and Sextilis (August). Each month had 29 days, except February with 28 and March, May, July, and October with 31. The first, fifth and thirteenth days of each month were called the Kalends (Kalendae), Nones (Nonae), and Ides (Idus) respectively, except that in March, May, July, and October the Nones fell on the seventh and the Ides on the fifteenth. I have kept these names in translation.
The calendar was adjusted by means of intercalation. At the discretion of the College of Pontiffs, usually every other year, an intercalary month of 23 or 22 days was inserted after 24 or 23 February. But in the years immediately before the Civil War the College neglected this procedure, so that by 46 the calendar was well over two months in advance of the sun. Julius Caesar rectified the situation by inserting two intercalary months totalling 67 days between November and December of that year in addition to the traditional one in February. He also gave the months their present numbers of days, thus almost obviating