March remained the first month of the year until 153 bc. From then the official year of the consuls and most other Roman magistrates began on 1 January. March, May, Quintilis (July), and October had 31 days each (Nones on 7th, Ides on 15th), February 28, and the rest 29 (Ides on 13th): total 355.
To intercalate, February was shortened to 23 or 24 days and followed by an intercalary month of 27 days. This intercalating was so clumsily done that by the time of Caesar the civic year was about three months ahead of the solar. In his capacity as pontifex maximus, and advised by the astronomer Sōsigenēs, he intercalated sufficent days to bring the year 46 bc to a total of 445 days, which was thus ‘the last year of the muddled reckoning’. From the next year onwards the Egyptian solar calendar (see time‐reckoning) was adapted to Roman use.
Subjects: Classical studies