Prehistoric calendar
The original Roman calendar is usually believed to have been an observational lunar calendar whose months ended and began from the See more

The nundinae were the market days which formed a kind of weekend in Rome, Italy, and some other parts of Roman territory. By Roman inclusive counting, they were reckoned as "ninth days" although they actually occurred every eighth day. Because the … See more

The Republican calendar only had 355 days, which meant that it would quickly unsynchronize from the solar year, causing, for example, agricultural festivals to occur out of … See more

The continuity of names from the Roman to the Gregorian calendar can lead to the mistaken belief that Roman dates correspond to Julian … See more

Roman dates were counted inclusively forward to the next one of three principal days within each month:
• Kalends (Kalendae or Kal.), the 1st day of each month See more

The names of Roman months originally functioned as adjectives (e.g., the January kalends occur in the January month) before being treated … See more

As mentioned above, Rome's legendary 10-month calendar notionally lasted for 304 days but was usually thought to make up the rest of the solar year during an unorganized winter period. The unattested but almost certain lunar year and the pre-Julian civil year … See more