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. People who like 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 HE idea was first thought of by the scientist Cesare Emiliani in 1993 (11993 HE).
Reasons for wanting a new 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 calculation of lengths of time difficult.
- 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.
Instead, 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 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
|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|
|33||+0033||10033 HE||Crucifixion of Jesus.|
|632||+0632||10632 HE||Death of Muhammad.|
|1582||+1582||11582 HE||Adoption of Gregorian calendar.|
|10000||+10000||20000 HE||Y10K problem.|
- 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. 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.