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.
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. 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.
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. 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.
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.
|Gregorian year||ISO 8601||Holocene year||Event|
|10001 BC/BCE||−10000[a]||0 HE||Beginning of the Holocene Era|
|9701 BC/BCE||−9700||300 HE||End of the Pleistocene and beginning of the Holocene epoch|
|4714 BC/BCE||−4713||5287 HE||Epoch 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:10|
|3761 BC/BCE||−3760||6240 HE||Beginning of the Anno Mundi era in the Hebrew calendar:11|
|3102 BC/BCE||−3101||6899 HE||Beginning of the Kali Yuga era in Hindu cosmology|
|45 BC/BCE||−0044||9956 HE||Introduction of the Julian calendar|
|1 BC/BCE||+0000||10000 HE||Year zero at ISO 8601|
|AD 1/1 CE||+0001||10001 HE||Beginning of the Common Era (Anno Domini), from the (incorrect) estimate by Dionysus of the Incarnation of Jesus|
|AD 622 CE, 1 AH||+0622||10622 HE||Migration of Muhammad from Mecca to Medina (Hegira), starting the Islamic calendar|
|AD 1582 CE||+1582||11582 HE||Introduction of the Gregorian calendar:47|
|AD 1912 CE||+1912||11912 HE||Epoch of the Juche and Minguo calendars|
|AD 1950 CE||+1950||11950 HE||Epoch of the Before Present dating scheme:190|
|AD 1970 CE||+1970||11970 HE||Unix Epoch|
|AD 1993 CE||+1993||11993 HE||Publication of the Holocene calendar|
|AD 2018 CE||+2018||12018 HE||Current year|
|AD 10000 CE||+10000||20000 HE|
- Emiliani 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.
- 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
- Emiliani, Cesare (1994). "Calendar reform for the year 2000". Eos. 75 (19): 218. Bibcode:1994EOSTr..75..218E. doi:10.1029/94EO00895.
- 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.
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- "The Open Group Base Specifications Issue 7, Rationale, section 4.16 Seconds Since the Epoch". The OpenGroup. 2018.
- David Ewing Duncan (1999). The Calendar. pp. 331–332. ISBN 1-85702-979-8.
- Duncan Steel (2000). Marking Time: The Epic Quest to Invent the Perfect Calendar. John Wiley and Sons. pp. 149–151. ISBN 978-0-471-29827-4.
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- "A New History for Humanity – The Human Era" - YouTube video explaining the Holocene Calendar by Kurzgesagt
- "News and comment", Geology Today, 20/3 (2004) 89–96.
- Timeline of World History
- Geologic TimeScale Foundation: GSSP Table, engineering.purdue.edu
- Comparison of some historic dates in the gregorian and the Holocene calendar