AD can’t be after death because that would leave a 30 year gap between BC and AD.
So AD is the year of His birth and BC are all the years before His birth.
I did mention I was born in Oklahoma right? We had our own set of memes to remember things. We had good teachers but poor connection to the world. I started 1st grade in 1942 and for the first six years of school I remember that the population of the United States was taught to us as being 93,000,000 but it was actually; The Sixteenth United States Census,(1940) conducted by the Census Bureau, determined the resident population of the United States to be 132,164,569
As Jr. Samples always said, Truth is Stranger than Fact.