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 year 2018 in the Holocene calendar is 12,018 HE. The HE scheme was first proposed by Cesare Emiliani in 1993.[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:

  • The Anno Domini era is based on the erroneous estimation of the birth year of Jesus. The era places Jesus's birth year in AD 1, but modern scholars have determined that he was likely born in or before 4 BC. Emiliani argued that replacing it with the approximate beginning of the Holocene makes more sense.
  • The birth date of Jesus is a less universally relevant epoch event than the approximate beginning of the Holocene.
  • The years BC/BCE are counted down when moving from past to future, making calculation of time spans difficult.
  • The Anno Domini era has no year zero, with 1 BC followed immediately by AD 1, complicating the calculation of timespans further. This is equally true of the Common Era, its non-religious equivalent.

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 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 1994 he mentioned that there was no agreement on the date of the start of the Holocene epoch with contemporary estimates ranging between 12,700 and 10,970 years BP.[2] Since then, scientists have improved their understanding of, and can now more accurately date the beginning of, the Holocene. A consensus viewpoint has solidified and was formally adopted by the IUGS in 2013. Current estimates place its start at 11,700 years before 2000 (9701 BC), about 300 years more recent than the epoch of the Holocene calendar.[3]


Conversion from Julian or Gregorian AD years to the Human Era can be achieved by adding 10,000 to the AD year. The current year of AD 2018 can be transformed into a Holocene year by adding the digit "1" before it, making it 12,018 HE. BC years are converted by subtracting the BC year from 10,001. A useful validity check is that the last single digits of BC and HE equivalent pairs must add up to 1 or 11.

Comparison of some historic dates in the Gregorian and the Holocene calendar[disputed ]
Gregorian yearISO 8601Holocene yearEvent
10001 BC/BCE−10000[a]0 HEBeginning of the Holocene Era
9701 BC/BCE−9700300 HEEnd of the Pleistocene and beginning of the Holocene epoch[3]
4714 BC/BCE−47135287 HEEpoch of the Julian day system: Julian day 0 starts at Greenwich noon on January 1, 4713 BC/BCE of the proleptic Julian calendar, which is November 24, 4714 BC/BCE in the proleptic Gregorian calendar[4]:10
3761 BC/BCE−37606240 HEBeginning of the Anno Mundi era in the Hebrew calendar[4]:11
3102 BC/BCE−31016899 HEBeginning of the Kali Yuga era in Hindu cosmology[citation needed]
45 BC/BCE−00449956 HEIntroduction of the Julian calendar
1 BC/BCE+000010000 HEYear zero at ISO 8601
AD 1/1 CE+000110001 HEBeginning of the Common Era (Anno Domini), from the (incorrect) estimate by Dionysius of the Incarnation of Jesus
AD 622 CE, 1 AH+062210622 HEMigration of Muhammad from Mecca to Medina (Hegira), starting the Islamic calendar[5][6]
AD 1582 CE+158211582 HEIntroduction of the Gregorian calendar[4]:47
AD 1912 CE+191211912 HEEpoch of the Juche[citation needed] and Minguo calendars[citation needed]
AD 1950 CE+195011950 HEEpoch of the Before Present dating scheme[7]:190
AD 1970 CE+197011970 HEUnix Epoch[8]
AD 1993 CE+199311993 HEPublication of the Holocene calendar
AD 2018 CE+201812018 HECurrent year
AD 10000 CE+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[edit]


  1. ^ a b c 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. ^ a b Emiliani, Cesare (1994). "Calendar reform for the year 2000". Eos. 75 (19): 218. Bibcode:1994EOSTr..75..218E. doi:10.1029/94EO00895.
  3. ^ a b 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. ^ a b c Dershowitz, Nachum; Reingold, Edward M. (2008). Calendrical Calculations (3rd ed.). Cambridge University Press. ISBN 978-0-521-70238-6.
  5. ^ Aisha El-Awady (2002-06-11). "Ramadan and the Lunar Calendar". Islamonline.net. Retrieved 2006-12-16.
  6. ^ 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.
  7. ^ 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.
  8. ^ "The Open Group Base Specifications Issue 7, Rationale, section 4.16 Seconds Since the Epoch". The OpenGroup. 2018.

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