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 shifted from a hunter-gatherer lifestyle to agriculture and fixed settlements. The current year by the Gregorian calendar, AD , is HE in the Holocene calendar. The HE scheme was first proposed by Cesare Emiliani in 1993 (11993 HE), though similar proposals to start a new calendar at the same date had been put forward decades earlier. Emiliani thereby dismissed his original proposal to align the era with the 7980-year Julian cycles, i.e. start with the epoch in 4713 BCE (5288 HE).
Overview Cesare Emiliani's proposal for a calendar reform sought to solve a number of alleged problems with the current era, also called the Common Era, which numbers the years of the commonly accepted world calendar. These issues include: The era has no year "zero", with 1 BC followed immediately by AD 1, making calculation of time spans difficult. The years BC/BCE are counted down when moving from past to future, complicating the calculation of timespans further. The birth date of Jesus is a less universally relevant epoch event than the approximate beginning of the Holocene. The era is based on the erroneous or contentious estimates of the birth year of Jesus of Nazareth. The era places Jesus's birth year in AD 1, but modern scholars have determined that it is more likely that he was born in or before 4 BC. Emiliani argued that replacing the contested date with the approximate beginning of the Holocene makes more sense.
Instead, HE uses the "beginning of human era" as its epoch, arbitrarily defined as 10,000 BC and 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 later proposed that the start of the Holocene should be fixed at the same date as the beginning of his proposed era.
Accuracy When Emiliani discussed the calendar in a follow-up article in 1994, he mentioned that there was no agreement on the date of the start of the Holocene epoch, with estimates at the time ranging between 12,700 and 10,970 years BP. Since then, scientists have improved their understanding of the Holocene on the evidence of ice cores and can now more accurately date its beginning. A consensus view was formally adopted by the IUGS in 2013, placing its start at 11,700 years before 2000 (9701 BC), about 300 years more recent than the epoch of the Holocene calendar. Though not aligning with this consensus, a first year of 10,000 BCE does enable easier conversion from Common Era dates.
Equivalent proposals In 1924 Gabriel Deville proposed the use of Calendrier nouveau de chronologie ancienne (CNCA), which would start 10,000 years before AD 1, which is identical to Emiliani's much later proposal.
Since 1929, Dievturība adherents use Latviskā ēra (the Latvian Era) which begins at the same point; this coincides with the first inhabitants’ influx to the territory of present Latvia (10500–10047 BCE). According to the Latvian Era, is written for CE. Detailed explanation of Latvian Era by Ernests Brastiņš was first published in 1934.
In 1963 E.R. Hope proposed the use of Anterior Epoch (AE), which also begins at the same point.
Conversion Conversion from Julian or Gregorian calendar years to the Human Era can be achieved by adding 10,000 to the AD/CE year. The present year, , can be transformed into a Holocene year by adding the digit "1" before it, making it HE. Years BC/BCE are converted by subtracting the BC/BCE year number from 10,001.
+ Calendar epochs and milestones in the Holocene calendar Event 10002 BC −10001 −1 HE 10001 BC −10000 0 HE 10000 BC −9999 1 HE Epoch of the Holocene calendar era. Equivalent to 11949 Before Present (BP) 9701 BC −9700 300 HE End of the Pleistocene and beginning of the Holocene (geological epoch), equivalent to 11650 BP 5509 BC −5508 4492 HE Beginning of the Byzantine calendar 4714 BC −4713 5287 HE Epoch of the Julian day system: Julian day 0 starts at Greenwich noon on January 1, 4713 BC of the proleptic Julian calendar, which is November 24, 4714 BC in the proleptic Gregorian calendar This is equivalent to 6,663 BP. 3761 BC −3760 6240 HE Beginning of the calendar era in the Hebrew calendar ~3300 BC n/a ~6700 HE Approximate beginning of the Bronze Age 3102 BC −3101 6899 HE Beginning of the Kali Yuga in Hindu cosmologySee: Matchett, Freda, "The Puranas", p 139 and Yano, Michio, "Calendar, astrology and astronomy" in 2250 BC −2249 7751 HE Beginning of the Meghalayan, the current and latest of the three stages in the Holocene. ~1200 BC n/a ~8800 HE Approximate beginning of the Iron Age 753 BC −0752 9248 HE Beginning of the ab urbe condita543 BC−05429457 HEBeginning of the Buddhist calendar 45 BC −0044 9956 HE Introduction of the Julian calendar 1 BC 0000 10000 HE Year zero at ISO 8601 1 AD 0001 10001 HE Beginning of the Common Era and , from the estimate by Dionysius Exiguus 622 0622 10622 HE Migration of Muhammad from Mecca to Medina, starting the Islamic calendar at 1 AH638063810638 HEBeginning of the Lesser Era calendar (Chulasakarat calendar) 1582 1582 11582 HE Introduction of the Gregorian calendar 1912 1912 11912 HE Epoch of the Juche and Republic of China calendars 1950 1950 11950 HE Epoch of the Before Present dating scheme 1960 1960 11960 HE UTC Epoch 1970 1970 11970 HE Unix Epoch 1993 1993 11993 HE Publication of the Holocene calendar HE Current year 10000 +10000 20000 HE
See also After the Development of Agriculture, a calendar system that adds 8000 years to the Common Era. , a calendar system that adds 4000 years to the Common Era. Before Present, the notation most widely used today in scientific literature for dates in prehistory. Calendar reform Astronomical year numbering, 1 BC is the epoch because there is no year zero in Anno Domini.
References
Further reading