Roman Dates

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Conversion table: (Excel) (HTML) (CSV)                                                   Fasti consulares: (Excel) (HTML)

How to Read the Conversion Table

Each row in the conversion table corresponds to a Roman civil year, in principle identified by its Varronian year number. The Julian years corresponding to the first and last day of the corresponding Roman year are given on either side. The entries in the row give the Julian date for the start of each Roman month in the corresponding Julian year. Additionally, the nundinal letter(s) for the market day in each civil year are also given.

Finally, supplementary infomation useful for interpreting the tables is colour-coded, or encoded in the font style. The details of this is explained further below; see here for the colour coding of the body of the table.

Roman Month Names

The Roman month names are given across the top in the form used in the Republic. They are repeated on the boundary between years B.C. and A.D. in the form used in the early Empire. The following changes occurred in the period covered by the tables:

Equivalent Julian Years

The left hand column gives the Julian year B.C. in which the corresponding Roman year began. This may be the same as the Julian year usually equated with the Roman year, or one year earlier.

The rightmost column but one gives the Julian year B.C. in which the corresponding Roman civil year ended. This may be the same as the Julian year usually equated with the Roman civil year, or one year later.

Varronian Year

The second column gives the Varronian year number A.U.C. (ab urbe condita) for the Roman civil year on Kal. Ian., assuming that A.U.C. 1 = 753 B.C. The third column from the right gives the Varronian year number for the Roman civil year on Kal. Dec. The bolded Varronian year number is the number that identifies the civil year.

The two columns differ before A.U.C. 601 = 153 B.C. because the Varronian year is accounted as the consular year. The start of the consular year changed from time to time. It started on Id. Mart. before A.U.C. 601 = 153 and Kal. Ian. thereafter; AUC 600 was a short year running from Id. Mart. to prid. Kal. Ian. It is held here, as by most chronologists (though not by Brind'Amour) that it started on Kal. Mai. before A.U.C. 532 = 222. The Varronian year boundaries in the period before A.U.C. 601 are indicated by a blue line. During this period the second column gives the Varronian year applying on Kal. Ian, while the third-last column gives the Varronian year for the period Id. Mart. (or Kal. Mai.) to December, which is one year later.

The Varronian year is given here partly for convenience and partly because it is widely used by modern Roman chronologists. It was not ordinarily used by the Romans themselves at this time. Roman years were identified eponymously by the presiding consuls. Eponym lists, known as fasti consulares, were maintained by the Romans and survived into medieval times. These allow us accurately to date the year by consular name, although they are not considered fully reliable before about 300 B.C. An example of a complete list, including replacement ("suffect") consuls, is shown here.

Date Conversions

Each row entry in the main part of the first two tables gives the Julian date for the start of the corresponding Roman civil month in the applicable Varronian year.

The following colour conventions indicate the certainty of converted dates:

The following colour conventions indicate synchronistic data in the corresponding month:

The following colour conventions apply to cell backgrounds:

Calendrical Cross Conversions


1 January in this month (Julian New Year)


29 February in this month (Julian Leap Year)


1 Thoth in this month (Egyptian New Year)

Reliability of Regular Pre-Julian Years

Certainly regular year (355 days)

Regular if inferred Lex Acilia is correct

Regular if additionally festival date in next year implies a candidate intercalation

Regular if additionally a nundinal argument is correct

Modelled as regular -- best guess

Bissextile Days 45 - 8 B.C.


Triennial bissextile day this month

The following additional colour conventions apply:

Nundinal Letters

The rightmost column gives the nundinal letters in the sequence A-H associated with the Roman market day in the corresponding civil year. This is one of the most important tools available for validating a reconstruction of Roman chronology.

The following conventions are used:

It should be noted that the nundinal letter given here, or the first nundinal letter of a pair, as appropriate, is effectively the complement, modulo 8, of the letter given by most Roman chronologists. The standard convention would represent the nundinal letter of Kal. Ian. if the cycle of letters was uninterrupted, like the modern week. However, the cycle was actually reset at the start of every civil year, and the important datum is not Kal. Ian. but the market day. The standard convention not only does not represent the market day, except by coincidence, but it is also anachronistic. The values shown here reflect actual Roman practice rather than the normal modern convention. The two may be converted as follows:

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