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 (or CE) numbering scheme, placing its first year near the beginning of the Holocene geological epoch and the Neolithic Revolution, when humans transitioned from a hunter-gatherer lifestyle to agriculture and fixed settlements. The current year in the Holocene calendar is 12,017 HE. The HE scheme was first proposed by scientist Cesare Emiliani in 1993.
Cesare Emiliani's proposal for a calendar reform sought to solve a number of alleged problems with the current Anno Domini era, which number the years of the commonly accepted world calendar. These issues include:
Instead, HE uses the "beginning of human era" as its epoch, arbitrarily defined as 10,000 BC 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.
Scientists have improved their understanding of and can now more accurately date the beginning of the Holocene. A consensus viewpoint has solidified and was formally adopted by the IUGS in 2013. Current estimates place its start at 11.7 thousand years before AD 2000.
This conflicts with the dating proposed for HE and means that it is not clear how it would be altered from the 1993 proposal in Nature. In the twenty-odd years after 1993 it has mostly been a curiosity and has not gained widespread use even within the geological, palaeontological or archaeological scientific communities.