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The Holocene calendar, Human Era count or Jōmon Era count (Japan) uses a dating system similar to astronomical year numbering but adds 10,000, placing a year 0 at the start of the Jōmon Era (JE), the Human Era (HE, the beginning of human civilization) and the aproximate beginning of the Holocene Epoch (HE) for easier geological, archaeological and, especially for Japanese regnal years, historical dating. The current year can be transformed by simply placing a 1 before it (i.e.: 12024). The system is not officially acknowledged and so far is only used within some Japanese academic circles. The Human Era proposal was first made by Cesare Emiliani in 1993. [1]

Western Motivation[]

Cesare Emiliani’s proposal for a calendar reform sought to solve a number of problems with the current Gregorian Calendar, which currently serves as the commonly accepted world calendar. The issues include:

  • The Gregorian Calendar starts at the presumed year of the birth of Jesus Christ. This Christian aspect of the Gregorian calendar (especially the use of Before Christ and Anno Domini) can be irritating, or even offensive, to non-Christian people.[2]
  • 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 count 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 sets the start, the epoch, of the current era to 10,000 BC. This is a first approximation of the start of the current geologic epoch, not coincidentally called 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 around 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 to Holocene from Gregorian AD (CE) dates can be achieved by adding 10,000. BC (BCE) dates are converted by subtracting the BC year from 10,001.

Gregorian Conversion
Gregorian years Holocene Epoch
Human Era
c.30000 BC c.-20000 HE or c.20000 BHE
10001 BC 0 HE
10000 BC 1 HE
1 BC 10000 HE
AD 1 10001 HE
AD 2024 12024 HE
AD 10000 20000 HE

Japanese Motivation[]

In Japan, to supplant the current use of regnal years while retaining the nengō system’s way to count years forward from the start, gannen of a new era, it has been proposed to introduce a “Jōmon Era” (JE) count to facilitate archaeological dating.

Nengō period conversion
Period Gregorian years Jōmon Era
Jōmon Gannen 10000 BC 1 JE
Incipient Jōmon 10000 – 7500 BC 1 – 2500 JE
Initial Jōmon 7500 – 4000 BC 2501 – 6000 JE
Early Jōmon 4000 – 3000 BC 6001 – 7000 JE
Middle Jōmon 3000 – 2000 BC 7001 – 8000 JE
Late Jōmon 2000 – 1000 BC 8001 – 9000 JE
Final Jōmon 1000 – 300 BC 9001 – 9700 JE
Japan Imperial power founded 660 BC 9341 JE
Yayoi period 251 BC – 250 AD 9750 – 10250 JE


  • David Ewing Duncan (1999). The Calendar. pp. 331–332. Template:Hide in printTemplate:Only in print. 
  • Cesare Emiliani (1993). Calendar reform. Nature. pp. 366–716.