Probably, but not in the way the show portrays.
In early christianity, people used to believe that Jesus was born around 1 BC to match the 33 years old that, according to tradition, he was when crucified in 33 AD.
Now, most scholars believe Jesus was born between 13 BC and 4 BC, giving a margin of 3 to 12 years of error in the gregorian calendar.
In "Charmed", however, it's established the calendar is just a few months away.