How do you count BC years?
BC + AD - 1
You have to subtract 1 after adding the year BC to the AD year.
There is no year Zero, so the calendar is not a proper timeline.
This is not a matter of interpretation (like the new millennium
If you were born in 1 B.C., then you were one year old in A.D.
1. That's 1 + 1 - 1.
If the start and end years are both BC, then it's a simple
subtraction of the smaller number from the larger number, just as
you would calculate your own age today.
Note that "BC" is properly written after the year, but "AD"
(Anno Domini) goes before the year. If you use the more inclusive
"Common Era" notation, then both "CE" and "BCE" go after the