Originally Posted by Josseppie
Technically I would say there was but just as in BC at the time they did not know it was 0. Or even care for that matter.
The point is, if we can determine in retrospect that a certain emperor was in power from May 1, 1 BCE until May 1, 1 CE, was his reign one year or two years? Or, if the emperor is known to have died in 1 CE after being in power for two years, do we reckon that he became emperor in 1 BCE (counting zero), or in 2 BCE?
Actually, as it turns out, historians and astronomers differ:
So if a historical reference were found to a person who observed a certain astronomical event that occurred in 10 BCE, historians would have to say that that person was in that place in 9 BCE, historical time, matching all other historical events that are calculated to be in 9 BCE.