Decimal calendar
Encyclopedia
A decimal calendar contains either ten days per week, a multiple of ten days in a month, or ten months per year. Examples that have been adopted are the calendar of Romulus
, the Egyptian calendar
, the Alexandrian calendar, the Coptic calendar
, the Ethiopian calendar
, and the French Republican Calendar
.
adopted sometime after Romulus and Remus
founded the city of Rome
in 753 BC, when Romulus killed Remus. According to Roman writers, including Censorinus
and Macrobius, it had ten of the twelve months in our modern calendar, March through December, but it only had 304 days in its year. The remaining days needed to form a solar year were winter days not assigned to any month. It only lasted until about 700 BC when King Numa
, the successor of Romulus, added the winter months of January and February and rearranged the number of days in each month, creating the Roman calendar
.
, is the Egyptian calendar with an additional sixth epagomenal or leap day added to the end of the year, as decreed in 25 BC by the Roman emperor Augustus
five years after he conquered Egypt
. The Coptic calendar is the Alexandrian calendar as adopted by the Coptic Church at the beginning of the fourth century. The Ethiopian calendar is the Alexandrian calendar as adopted by the Ethiopian Church during the fourth century. Both the Coptic and Ethiopian calendars are still used today.
in 1793, was a modern version of the Egyptian/Alexandrian calendar. It consisted of a 12-month year, with each month consisting of three 10-day weeks, called décades, plus five or six sansculottides
days at the end of the year. It was utilized as the official calendar of France
for a period of twelve years, but was abolished by Napoleon on January 1, 1806.
does not have either ten-day weeks or ten-month years, so a few decimal calendars have been proposed by individuals to create a more rational calendar.
But none have gained any level of public acceptance, and the cost of any proposed conversion would far outweigh the savings that any might deliver.
Roman calendar
The Roman calendar changed its form several times in the time between the founding of Rome and the fall of the Roman Empire. This article generally discusses the early Roman or pre-Julian calendars...
, the Egyptian calendar
Egyptian calendar
The ancient civil Egyptian calendar had a year that was 360 days long and was divided into 12 months of 30 days each, plus five extra days at the end of the year. The months were divided into three weeks of ten days each...
, the Alexandrian calendar, the Coptic calendar
Coptic calendar
The Coptic calendar, also called the Alexandrian calendar, is used by the Coptic Orthodox Church and still used in Egypt. This calendar is based on the ancient Egyptian calendar...
, the Ethiopian calendar
Ethiopian calendar
The Ethiopian calendar , also called the Ge'ez calendar, is the principal calendar used in Ethiopia and also serves as the liturgical calendar for Christians in Eritrea belonging to the Eritrean Orthodox Church, Eastern Catholic Church and Lutheran Evangelical Church of Eritrea...
, and the French Republican Calendar
French Republican Calendar
The French Republican Calendar or French Revolutionary Calendar was a calendar created and implemented during the French Revolution, and used by the French government for about 12 years from late 1793 to 1805, and for 18 days by the Paris Commune in 1871...
.
Calendar of Romulus
The only calendar with a ten-month year was the calendar of RomulusRoman calendar
The Roman calendar changed its form several times in the time between the founding of Rome and the fall of the Roman Empire. This article generally discusses the early Roman or pre-Julian calendars...
adopted sometime after Romulus and Remus
Romulus and Remus
Romulus and Remus are Rome's twin founders in its traditional foundation myth, although the former is sometimes said to be the sole founder...
founded the city of Rome
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
in 753 BC, when Romulus killed Remus. According to Roman writers, including Censorinus
Censorinus
Censorinus, Roman grammarian and miscellaneous writer, flourished during the 3rd century AD.He was the author of a lost work De Accentibus and of an extant treatise De Die Natali, written in 238, and dedicated to his patron Quintus Caerellius as a birthday gift...
and Macrobius, it had ten of the twelve months in our modern calendar, March through December, but it only had 304 days in its year. The remaining days needed to form a solar year were winter days not assigned to any month. It only lasted until about 700 BC when King Numa
Numa Pompilius
Numa Pompilius was the legendary second king of Rome, succeeding Romulus. What tales are descended to us about him come from Valerius Antias, an author from the early part of the 1st century BC known through limited mentions of later authors , Dionysius of Halicarnassus circa 60BC-...
, the successor of Romulus, added the winter months of January and February and rearranged the number of days in each month, creating the Roman calendar
Roman calendar
The Roman calendar changed its form several times in the time between the founding of Rome and the fall of the Roman Empire. This article generally discusses the early Roman or pre-Julian calendars...
.
Egyptian, Alexandrian, Coptic, and Ethiopian calendars
The Egyptian calendar of the first three millennia BC had twelve months of 30 days each, consisting of three ten-day weeks, plus five epagomenal days at the end of the year. The Alexandrian calendar, named for the city of AlexandriaAlexandria
Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...
, is the Egyptian calendar with an additional sixth epagomenal or leap day added to the end of the year, as decreed in 25 BC by the Roman emperor Augustus
Augustus
Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...
five years after he conquered Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
. The Coptic calendar is the Alexandrian calendar as adopted by the Coptic Church at the beginning of the fourth century. The Ethiopian calendar is the Alexandrian calendar as adopted by the Ethiopian Church during the fourth century. Both the Coptic and Ethiopian calendars are still used today.
French Republican Calendar
The French Republican Calendar, which was introduced along with decimal timeDecimal time
Decimal time is the representation of the time of day using units which are decimally related. This term is often used to refer specifically to French Revolutionary Time, which divides the day into 10 decimal hours, each decimal hour into 100 decimal minutes and each decimal minute into 100 decimal...
in 1793, was a modern version of the Egyptian/Alexandrian calendar. It consisted of a 12-month year, with each month consisting of three 10-day weeks, called décades, plus five or six sansculottides
Sansculottides
The Sansculottides are holidays following the last month of the year on the French Republican Calendar which was used following the French Revolution from approximately 1793 to 1805....
days at the end of the year. It was utilized as the official calendar of France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
for a period of twelve years, but was abolished by Napoleon on January 1, 1806.
Reform calendars
The modern Gregorian calendarGregorian calendar
The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...
does not have either ten-day weeks or ten-month years, so a few decimal calendars have been proposed by individuals to create a more rational calendar.
But none have gained any level of public acceptance, and the cost of any proposed conversion would far outweigh the savings that any might deliver.