How do people know how to record dates BC or BCE?

Historians use historical records written at the time. So if we take Augustus as an example records tell us who the consul was at the time of his birth, the ages of his parents, etc. Then the historians look at recorded events in his reign such as the Battle of Actium occurred when Augustus was X years of age. Historians also look at what was happening in other cultures at the same time and correlate the events such as X event happened during the Y Olympiad.

Recorded astronomical events also play a part in dating such as Mars, Venus and Jupiter being closely aligned. Since the orbits of these planets are known mathematics can be used to figure when the planets appear at the same time in certain constellations. If we take the pyramids as an example modern astronomers can figure out when Thuban was the pole star.

In addition there is Carbon 14 dating which is used to test organics.

You can figure out when Henry VIII was born by starting with the current Queen of England and counting backward using the number of years her predecessors reigned and their ages when they died. Start with Elizabeth's age and the number of years she has been queen, the age of her father when she was born, etc.

It's not an exact date. It's back dated from today's calendar.

BC refers to Before Christ while BCE means "Before the Common Era" which is the old AD (Anno Domini).

Either way, the calendar is off by 4-5, maybe even 6 years.

Jesus wasn't born in year 1. He was born in 4, 5, or maybe even 6 BC. We know this now because Herod, who had the babies killed trying to kill the Messiah, died in 4 BC.

Coins didn't have dates on them either. They had the leaders (kings, etc) images or symbols imprinted on them.

Also, a year had only 10 months. There was no July (Julius) or August (Octavious/Augustus) until the Caesars.

Lots of people don't realize that September (Sep means 7), October (Octo means 8), November (Nove means 9), and December (Deca means 10) were actually pushed out by July and August, making a 12 month year.

<when the people at the time didn't know they were in BC or BCE> Do you understand that there are many different calendars in the world, even in current use, other than the one you use? We could start a brand new calendar right now, with this being year zero, and we'll use AN and BN for After Now and Before Now. The 9/11 attacks would have happened in the year 13 BN. It doesn't make a lick of difference whether people know what day it is on any particular calendar.

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BC is used primarily by Chistians, as in Before Christ, it's origins come from latin. The BCE is before common era, it's a way they get around having a reference to Christ in the date, used by atheist and others who deny the existence of Christ. By the way AD also comes from latin roots.

Depends on if they want to use the most common calendar and make a point about being christian or not. If you want to completely ignore religion, make your dates Before Present.

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