Holocene calendar

For the geological epoch, see Holocene.

The Holocene calendar, or Human era (HE), is a year numbering system that adds 10,000 years to the present Anno Domini (AD) or Common Era (CE) system. It puts the first year near the beginning of the Holocene epoch and the Neolithic revolution. Those who favour the HE system say that it makes for easier geological, archeological, dendrochronological and historical dating.

For example, the year 2022 can be made into a Holocene year by adding the number "1" before it, making it 12022 HE. The calendar was introduced by the scientist Cesare Emiliani in 1993 (11993 HE).

Arguments supporting the Holocene calendar include:

• In the Anno Domini system the birth of Jesus represents the year 1. People now think Jesus was born four years earlier.
• The years BC are counted down when moving from past to future, making it more difficult to calculate timespans across this divide.
• The Anno Domini system has no year zero, with 1 BC followed by year 1. It is important to not forget this when calculating lengths of time.

The HE starts at 10001 BC. This is a rough approximation of the start of the current geologic epoch, the Holocene or Recent period. Human settlements, first cities and agriculture probably started in this period. All important dates in human history can then be listed using a simple increasing date scale with smaller dates always before larger dates.

Conversion

Conversion to the Human 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 check is that the last single number of BC and HE equivalent pairs must add up to 1 or 11.

Gregorian years	ISO 8601	Human Era Holocene Epoch	Remarks
30001 BC	−30000	20000 BHE
10001 BC	−10000	0 HE
10000 BC	−9999	1 HE	Beginning of Holocene.
9001 BC	−9000	1000 HE
1000 BC	−0999	9001 HE
753 BC	−0999	9248 HE	Foundation of Rome.
100 BC	−0099	9901 HE	Birth of Julius Caesar.
10 BC	−0009	9991 HE
4 BC	−0003	9997 HE	Birth of Jesus.
2 BC	−0001	9999 HE
1 BC	+0000	10000 HE
1	+0001	10001 HE
2	+0002	10002 HE
10	+0010	10010 HE
33	+0033	10033 HE	Crucifixion of Jesus.
100	+0100	10100 HE
632	+0632	10632 HE	Death of Muhammad.
1000	+1000	11000 HE
1582	+1582	11582 HE	Adoption of Gregorian calendar.
2000	+2000	12000 HE
Current year
10000	+10000	20000 HE	Y10K problem.

Related pages

• Common Era
• Julian date (JD) – the interval of time in days and fractions of a day since January 1, 4713 BCE, Greenwich noon.

References

• David Ewing Duncan (1999). The Calendar. Fourth Estate. pp. 331–332. ISBN 1-85702-979-8.
• Duncan Steel (2000). Marking time: the epic quest to invent the perfect calendar. John Wiley. pp. 149–151. ISBN 978-0-471-29827-4.
• Günther A. Wagner (1998). Age determination of young rocks and artifacts: physical and chemical clocks in Quaternary geology and archeology. Springer. p. 48. ISBN 978-3-540-63436-2.
• "News and comment", Geology Today, 20/3 (2004) 89–96.
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