Editing Roman calendar (section)

===Legendary 10-month calendar===
The Romans themselves usually described their first organized year as one with ten fixed months,{{sfn|Macrobius|loc=Book I, Ch. 12, §3}}{{sfnp|Kaster|2011|p=137}} a decimal division fitting general Roman practice.{{sfnp|Mommsen & al.|1864|p=[https://archive.org/stream/historyrome00dickgoog#page/n242/mode/2up 217]}} There were four months of "31" days{{sfn|Macrobius|loc=Book I, Ch. 12, §3}}{{mdash}}March, May, Quintilis, and October{{mdash}}called "full months" ({{lang|la|[[wikt:pleni menses#Latin|pleni menses]]}}) and six months of "30" days{{sfn|Macrobius|loc=Book I, Ch. 12, §3}}{{mdash}}April, June, Sextilis, September, November, and December{{mdash}}called "hollow months" (''{{lang|la|[[wikt:cavi menses#Latin|cavi menses]]}}'').<ref>[[Censorinus]], [[Macrobius]], and [[Gaius Julius Solinus|Solinus]], cited in {{harvp|Key|1875}}</ref><ref name=mommy>{{harvp|Mommsen & al.|1864|p=[https://archive.org/stream/historyrome00dickgoog#page/n244/mode/2up 218]}}.</ref> These "304"&nbsp;days made up exactly 38&nbsp;[[nundinal cycle]]s. The months were kept in alignment with the moon, however, by counting the [[new moon]] as the last day of the first month and simultaneously the first day of the next month.{{sfnp|Grout|2023}} The system is usually said to have left the remaining two to three months of the year as an unorganized "winter", since they were irrelevant to the farming cycle.{{sfnp|Grout|2023}} [[Macrobius]] claims the 10-month calendar was fixed and allowed to shift until the summer months were completely misplaced, at which time additional days belonging to no month were simply inserted into the calendar until it seemed things were restored to their proper place.{{sfn|Macrobius|loc=Book I, Ch. 12, §39}}{{sfnp|Kaster|2011|p=155}} [[Gaius Licinius Macer|Licinius Macer]]'s lost history apparently similarly stated that even the earliest Roman calendar employed intercalation.<ref name=censibility>[[Censorinus]], ''[[De Die Natali|The Natal Day]]'', [https://elfinspell.com/ClassicalTexts/Maude/Censorinus/DeDieNatale-Part2.html Ch. XX].</ref>{{sfn|Macrobius|loc=Book I, Ch. 13, §20}}{{sfnp|Kaster|2011|p=165}}

Later Roman writers usually credited this calendar to [[Romulus]],{{sfn|Macrobius|loc=Book I, Ch. 12, §§5 & 38}}{{sfnp|Kaster|2011|pp=137 & 155}} their [[Roman legend|legendary]] [[Kings of Rome|first king]] and [[culture hero]], although this was common with other practices and traditions whose origin had been lost to them. [[Censorinus]] considered him to have borrowed the system from [[Alba Longa]],<ref name=censibility/> his supposed birthplace. Some scholars doubt the existence of this calendar at all, as it is only attested in late Republican and Imperial sources and supported only by the misplaced names of the months from September to December.<ref name=rupparena>{{harvp|Rüpke|2011|p=[https://books.google.com/books?id=pThna2LDwDsC&pg=PA23 23]}}.</ref> [[Jörg Rüpke|Rüpke]] also finds the coincidence of the length of the supposed "Romulan" year with the length of the first ten months of the Julian calendar to indicate that it is an {{lang|la|[[a priori]]}} interpretation by late Republican writers.<ref name=rupparena/>

{| class="wikitable plainrowheaders" style="margin:1em auto;"
|+ Calendar of Romulus
|-
! scope="col" | English
! scope="col" | Latin
! scope="col" | Meaning
! scope="col" | Length in days{{sfn|Macrobius|loc=Book I, Ch. 12, §3}}{{sfnp|Kaster|2011|p=137}}
|-
| [[March]] || [[Martius (month)|Mensis Martius]] || Month of [[Mars (mythology)|Mars]]
| style="font-weight: bold;"| 31
|-
| [[April]] || [[Mensis Aprilis]] || Month of Apru ([[Aphrodite]])<ref>{{cite web | title=April | website=Dictionary.com Unabridged | publisher=Randomhouse Inc. | url=http://www.dictionary.com/browse/april | access-date=January 9, 2018}}</ref>
| 30
|-
| [[May]] || [[Mensis Maius]] || Month of [[Maia (mythology)|Maia]]<ref>{{cite web | title=May | website=Dictionary.com Unabridged | publisher=Randomhouse Inc. | url=http://www.dictionary.com/browse/may | access-date=January 9, 2018}}</ref>
| style="font-weight: bold;" | 31
|-
| [[June]] || [[Iunius (month)|Mensis Iunius]] || Month of [[Juno (mythology)|Juno]]
| 30 
|-
| [[July]] || [[Mensis Quintilis]]<br>Mensis Quinctilis{{sfnp|Blackburn & al.|1999|p=669}} || Fifth Month
| style="font-weight: bold;" | 31
|-
| [[August]] || [[Mensis Sextilis]] || Sixth Month
| 30
|-
| [[September]] || [[September (Roman month)|Mensis September]] || Seventh Month
| 30
|-
| [[October]] || [[October (Roman month)|Mensis October]] || Eighth Month
| style="font-weight: bold;" | 31
|-
| [[November]] || [[November (Roman month)|Mensis November]] || Ninth Month
| 30
|-
| [[December]] || [[December (Roman month)|Mensis December]] || Tenth Month
| 30
|- 
! scope="row" colspan="3" style="text-align: right;" | Length of the year:
! style="text-align: left;" | 304
|}

Other traditions existed alongside this one, however. [[Plutarch]]'s ''[[Parallel Lives]]'' recounts that [[Romulus]]'s calendar had been solar but adhered to the general principle that the year should last for 360&nbsp;days. Months were employed secondarily and haphazardly, with some counted as 20&nbsp;days and others as 35 or more.<ref name=gossipgirl/><ref name=worchestershire/> Plutarch records that while one tradition is that [[Numa Pompilius|Numa]] added two new months to a ten-month calendar, another version is that January and February were originally the last two months of the year and Numa just moved them to the start of the year, so that January (named after a peaceful ruler called [[Janus]]) would come before March (which was named for Mars, the god of war).<ref>{{harvp|Plutarch|loc=''Life of Numa'' section XIX}}</ref>

Rome's 8-day week, the [[nundinal cycle]], was shared with the [[Etruscans]], who used it as the schedule of royal audiences. It was presumably a part of the early calendar and was credited in [[Roman legend]] variously to [[Romulus]] and [[Servius Tullius]].

{{anchor|Numa|Calendar of Numa|Numan reform}}