Holocene calendar

"H.E." redirects here. For For other uses of H.E., see He (disambiguation), see H.E. (disambiguation).

"Holocene era" redirects here. For For the geological epoch, see Holocene Epoch, see Holocene era (disambiguation).

The Holocene calendar, popular term for the Holocene Era or Human Era, is a year numbering system similar to astronomical year numbering but adds 10,000, placing its first year at the start of the Human Era (HE, the beginning of human civilization) the approximation of the Holocene Epoch (HE, post Ice Age) for easier geological, archaeological, dendrochronological and historical dating. The current Gregorian year can be transformed by simply placing a 1 before it (ie: 12024). The Human Era was first proposed by Cesare Emiliani in 1993 (11993 HE).

Motivation

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

• The Anno Domini and Common Eras begin at the presumed year of the birth of Jesus Christ. This Christian aspect (especially the use of Before Christ and Anno Domini) can be offensive to non-Christians.
• Biblical scholarship is virtually unanimous that the birth of Jesus Christ would actually have been a few years prior to AD 1. This makes the calendar inaccurate insofar as Christian dates are concerned.
• There is no year zero as 1 BC is followed immediately by AD 1.
• BC years are counted down when moving from past to future, thus 44 BC is after 250 BC. This makes calculating date ranges in the Holocene era across the BC/AD boundary more complicated than in the HE.

Instead, HE places its epoch or year one of the current era to 10,000 BC. 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 entirely within this time. All key dates in human history can then be listed using a simple increasing date scale with smaller dates always occurring before larger dates.

Conversion

Conversion to the Holocene Era from Julian or Gregorian AD years can be achieved by adding 10,000. BC years are converted by subtracting the BC year from 10,001.

A useful validity check is that the last digit of BC and HE equivalents must add up to 1 or 11.

Events	Julian or Gregorian years	Holocene Era Human Era
End of the Paleolithic Period, All continents (except Antarctica) inhabited, Agriculture and the domestication of animals begins.	c. 10000 BC	c. 1 HE
Earliest walled city (Jericho)	c. 9000 BC	c. 1000 HE
First copper found in Middle East - beginning of Copper Age	c. 6000 BC	c. 4000 HE
Beginning of Indus Valley Civilization	c. 3000 BC	c. 7000 HE
Probable date of the completion of the first Egyptian pyramid	2611 BC	7390 HE
Beginning of Xia Dynasty in China	c. 2100 BC	c. 7900 HE
Foundation of Rome	753 BC	9248 HE
First Central American writing systems	c. 400 BC	c. 9600 HE
Empire of Asoka	273 BC	9728 HE
Imperial China, Qin dynasty	221 BC	9780 HE
Last year of BC era	1 BC	10000 HE
First year of Anno Domini era	AD 1	10001 HE
Migration Period begins, leading to the Fall of Rome	AD 300/476	10300/10476 HE
Turkic migrations begin	c. AD 500	c. 10500 HE
Muslim conquests begin	AD 632	10632 HE
Great Zimbabwe built	c. AD 1000	c. 11000 HE
Hindu-Arabic numerals introduced to Europe	AD 1202	11202 HE
Black Death decimates Asia and Europe	AD 1340s	11340s HE
European expansion and colonization begins	AD 1419	11419 HE
Fall of the Inca Empire	AD 1572	11572 HE
Second Industrial Revolution	c. AD 1850	c. 11850 HE
Second World War and nuclear fission	AD 1939-1945	11939-11945 HE
First human in space	AD 1961	11961 HE
Current year	AD 2024	12024 HE

See also

• Before Present
• Calendar Era
• Common Era
• Julian Period

References

• 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. pp. 149–151.
• Günther A. Wagner (1998). Age Determination of Young Rocks and Artifacts: Physical and Chemical Clocks in Quaternary Geology and Archeology. Springer. p. 48.
• Timeline of World History
• "News and comment", Geology Today, 20/3 (2004) 89–96.