The calendar most commonly used today places year 1 CE at a point in time during the Roman Empire. That system labels earlier human accomplishment "before" or assigns negative numbers.
Emiliani's HE calendar places year 1 HE much earlier, when humans were settling into agricultural communities (loosely matching the beginning of the geological Holocene Epoch). Calling any point in time "year 1" is somewhat arbitrary. EMILIANI set 1 HE exactly 10,000 years before 1 CE. With this calculator, you can convert between the BCE or BC and HE systems.
You can also download the free chrome extension from holocenetimestamp.org which automatically converts dates to HE in Wikipedia and other sites. Click here to see the extension.