Holocene calendar

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The Holocene calendar, also known as the Holocene Era or Human Era (HE), is a year numbering system that adds exactly 10,000 years to the currently dominant (AD/BC or CE/BCE) numbering scheme, placing its first year near the beginning of the Holocene geological epoch and the Neolithic Revolution, when humans transitioned from a hunter-gatherer lifestyle to agriculture and fixed settlements. The current year by the Gregorian calendar, AD 2020, is 12020 HE in the Holocene calendar. The HE scheme was first proposed by Cesare Emiliani in 1993 (11993 HE). [1]



Cesare Emiliani's proposal for a calendar reform sought to solve a number of alleged problems with the current Anno Domini era, which number the years of the commonly accepted world calendar. These issues include:

Instead, HE uses the "beginning of human era" as its epoch, arbitrarily defined as 10,000 BC denoted year 1 HE, so that AD 1 matches 10,001 HE. [1] This is a rough approximation of the start of the current geologic epoch, the Holocene (the name means entirely recent). The motivation for this is that human civilization (e.g. the first settlements, agriculture, etc.) is believed to have arisen within this time. Emiliani would later propose that the start of the Holocene be fixed at the same date as the beginning of his proposed era. [2]


Human Era proponents claim that it makes for easier geological, archaeological, dendrochronological, anthropological and historical dating, as well as that it bases its epoch on an event more universally relevant than the birth of Jesus. All key dates in human history can then be listed using a simple increasing date scale with smaller dates always occurring before larger dates. Another gain is that the Holocene Era starts before the other calendar eras, so it could be useful for the comparison and conversion of dates from different calendars.


When Emiliani discussed the calendar in a follow-up article in 1994, he mentioned that there was no agreement on the date of the start of the Holocene epoch, with estimates at the time ranging between 12,700 and 10,970 years BP. [2] Since then, scientists have improved their understanding of the Holocene on the evidence of ice cores and can now more accurately date its beginning. A consensus view was formally adopted by the IUGS in 2013, placing its start at 11,700 years before 2000 (9701 BC), about 300 years more recent than the epoch of the Holocene calendar. [3]

Equivalent proposals

In 1924 Gabriel Deville proposed the use of Calendrier nouveau de chronologie ancienne (CNCA), which would start 10,000 years before AD 1, identically to Emiliani's proposal. [4]

In 1963 E. R. Hope proposed the use of Anterior Epoch (AE), which also begins at the same point. [5]


Conversion from Julian or Gregorian calendar years to the Human Era can be achieved by adding 10,000 to the AD/CE year. The present year, 2020, can be transformed into a Holocene year by adding the digit "1" before it, making it 12,020 HE. Years BC/BCE are converted by subtracting the BC/BCE year number from 10,001.

Comparison of some historic dates in the Gregorian and the Holocene calendar
Gregorian year ISO 8601 Holocene yearEvent
10001 BC −10000 [lower-alpha 1] 0 HEBeginning of the Holocene Era
9701 BC −9700300 HEEnd of the Pleistocene and beginning of the Holocene epoch [3]
4714 BC −47135287 HE Epoch of the Julian day system: Julian day 0 starts at Greenwich noon on January 1, 4713 BC of the proleptic Julian calendar, which is November 24, 4714 BC in the proleptic Gregorian calendar [6] :10
3761 BC −37606240 HEBeginning of the Anno Mundi calendar era in the Hebrew calendar [6] :11
3102 BC −31016899 HEBeginning of the Kali Yuga in Hindu cosmology [7]
2250 BC −22497751 HEBeginning of the Meghalayan age, the current and latest of the three stages in the Holocene era. [8] [9]
45 BC −00449956 HEIntroduction of the Julian calendar
1 BC +000010000 HE Year zero at ISO 8601
AD 1 +000110001 HEBeginning of the Common Era and Anno Domini, from the estimate by Dionysius of the Incarnation of Jesus
622, 1  AH +062210622 HEMigration of Muhammad from Mecca to Medina (Hegira), starting the Islamic calendar [10] [11]
1582 +158211582 HEIntroduction of the Gregorian calendar [6] :47
1912 +191211912 HE Epoch of the Juche [ citation needed ] and Minguo calendars [ citation needed ]
1950 +195011950 HE Epoch of the Before Present dating scheme [12] :190
1960 +196011960 HE UTC Epoch
1970 +197011970 HE Unix Epoch [13]
1993 +199311993 HEPublication of the Holocene calendar
2020 +202012020 HECurrent year
10000 +1000020000 HE
  1. Emiliani [1] states his proposal "would make the year AD 1 into the year 10,001" but does not mention the Julian or Gregorian calendar. The proposal does not explicitly designate any particular date as the beginning of the era.

See also

Related Research Articles

<i>Anno Domini</i> Western calendar era

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Common Era (CE) is one of the year notations used for the Gregorian calendar, the world's most widely used calendar era. Before the Common Era (BCE) is the era before CE. BCE and CE are alternatives to the Dionysian BC and AD notations respectively. The Dionysian era distinguishes eras using the notations BC and AD. The two notation systems are numerically equivalent: "2020 CE" and "AD 2020" each describe the current year; "400 BCE" and "400 BC" are each the same year. The Gregorian calendar is used throughout the world today, and is an international standard for civil calendars.

An era is a span of time defined for the purposes of chronology or historiography, as in the regnal eras in the history of a given monarchy, a calendar era used for a given calendar, or the geological eras defined for the history of Earth.

The Julian calendar, proposed by Julius Caesar in AUC 708, was a reform of the Roman calendar. It took effect on 1 January AUC 709 , by edict. It was designed with the aid of Greek mathematicians and Greek astronomers such as Sosigenes of Alexandria.

Year Orbital period of the Earth around the Sun

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AD 1 Calendar year

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Julian day is the continuous count of days since the beginning of the Julian Period and is used primarily by astronomers, and in software for easily calculating elapsed days between two events.

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Anno Mundi Calendar era

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  1. 1 2 3 Emiliani, Cesare (1993). "Correspondence – Calendar Reform". Nature. 366 (6457): 716. Bibcode:1993Natur.366..716E. doi: 10.1038/366716b0 . Setting the beginning of the human era at 10,000 BC would date […] the birth of Christ at [25 December] 10,000
  2. 1 2 Emiliani, Cesare (1994). "Calendar reform for the year 2000". Eos. 75 (19): 218. Bibcode:1994EOSTr..75..218E. doi:10.1029/94EO00895.
  3. 1 2 Walker, Mike; Jonsen, Sigfus; Rasmussen, Sune Olander; Popp, Trevor; Steffensen, Jørgen-Peder; Gibbard, Phil; Hoek, Wim; Lowe, John; Andrews, John; Björck, Svante; Cwynar, Les C.; Hughen, Konrad; Kershaw, Peter; Kromer, Bernd; Litt, Thomas; Lowe, David J.; Nakagawa, Takeshi; Newnham, Rewi; Schwander, Jacob (2009). "Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records" (PDF). Journal of Quaternary Science. 24 (1): 3–17. Bibcode:2009JQS....24....3W. doi:10.1002/jqs.1227. Archived (PDF) from the original on 2013-11-04.
  4. Claude Naudin (2001). De temps en temps: Histoires de calendrier. ISBN   2-7028-4735-8.
  5. Hope, E. R. (1963). "The Arithmetical Reform of the Calendar, Part I". Journal of the Royal Astronomical Society of Canada. 57 (1): 14-23. Bibcode:1963JRASC..57...14H.
  6. 1 2 3 Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations (3rd ed.). Cambridge University Press. ISBN   978-0-521-70238-6.
  7. See: Matchett, Freda, "The Puranas", p 139 and Yano, Michio, "Calendar, astrology and astronomy" in Flood, Gavin (Ed) (2003). Blackwell companion to Hinduism. Blackwell Publishing. ISBN   978-0-631-21535-6.CS1 maint: extra text: authors list (link) CS1 maint: ref=harv (link)
  8. "ICS chart containing the Quaternary and Cambrian GSSPs and new stages (v 2018/07) is now released!" . Retrieved February 6, 2019.
  9. Conners, Deanna (September 18, 2018). "Welcome to the Meghalayan age" . Retrieved February 6, 2019.
  10. Aisha El-Awady (2002-06-11). "Ramadan and the Lunar Calendar". Islamonline.net . Retrieved 2006-12-16.
  11. Hakim Muhammad Said (1981). "The History of the Islamic Calendar in the Light of the Hijra". Ahlul Bayt Digital Islamic Library Project . Retrieved 2006-12-16.
  12. Currie Lloyd A (2004). "The Remarkable Metrological History of Radiocarbon Dating [II]" (PDF). Journal of Research of the National Institute of Standards and Technology. 109 (2): 185–217. doi:10.6028/jres.109.013. PMC   4853109 . PMID   27366605. Archived from the original (PDF) on 2010-12-06. Retrieved 2018-06-24.
  13. "The Open Group Base Specifications Issue 7, Rationale, section 4.16 Seconds Since the Epoch". The OpenGroup. 2018.

Further reading