Decimal calendar
{{Short description|A calendar which includes units of time based on the decimal system}}
A decimal calendar is a calendar which includes units of time based on the decimal system. For example, a "decimal month" would consist of a year with 10 months and 36.52422 days per month.
History
=Egyptian calendar=
{{Main|Egyptian calendar}}
The ancient Egyptian calendar consisted of twelve months, each divided into three weeks of ten days, with five intercalary days.{{cite web|title=Ancient Egyptian Calendar and Chronology |url=http://math.camden.rutgers.edu/extension01.pdf |publisher=Rutgers University |access-date=10 June 2012 |url-status=dead |archive-url=https://web.archive.org/web/20100719004746/http://math.camden.rutgers.edu/extension01.pdf |archive-date=19 July 2010 }}
=Calendar of Romulus=
{{Main|Calendar of Romulus}}
The original Roman calendar consisted of ten months; however, the calendar year only lasted 304 days, with 61 days during winter not assigned to any month.{{cite web |title=The Roman calendar |last1=Konstantin |first1=Bikos |first2=Vigdis |last2=Hocken |url=http://www.timeanddate.com/calendar/roman-calendar.html |publisher=Time and Date AS |place=Stavanger, Norway |access-date=10 June 2012}} The months of Ianuarius and Februarius were added to the calendar by Numa Pompilius in 700 BCE.
=French Republican Calendar=
{{Main|French Republican Calendar}}
The French Republican Calendar was introduced (along with decimal time) in 1793, and was similar to the ancient Egyptian calendar.{{cite journal|title=French Republican Calendar: Time, History and the Revolutionary Event|journal=Journal for Eighteenth-Century Studies|volume=35|pages=1–16|author=Sanja Perovic|doi=10.1111/j.1754-0208.2011.00408.x|year=2012}} It consisted of twelve months, each divided into three décades of ten days, with five or six intercalary days called sansculottides. The calendar was abolished by Napoleon on January 1, 1806.
Proposals
{{See also|Calendar reform}}
The modern Gregorian calendar does not use decimal units of time; however, several proposed calendar systems do. None of these have achieved widespread use.{{example needed|date=June 2019}}