The dating of life milestones – especially birth, death and marriage – for family members is crucial to discovering correct connections. But there are errors lurking out there to mislead the genealogist.
Errors in dates come chiefly in two flavors: intentional and unintentional. Sometimes people lie to authorities about their age. My mother did so to the U.S. Census-taker. I figured that out by comparing two censuses. The second one, ten years after the first, showed she had aged only eight years in the preceding ten. The earlier number was supplied most likely by her parents, the later one when she herself was interviewed. Of course, Beethoven’s father lied about his age to prove he was a prodigy, so sometimes you can’t even trust the parent. When it is intentional, you have to wonder what benefit accrued to the one making the “error.”
Another common error occurs when a witness to a death certificate or burial really doesn’t know the birth year of the deceased. The witness might think she was 76 when she died. It’s tempting for a researcher to subtract 76 from that death date to determine the year of her birth.
Put more trust in the date of the witnessed event (death/burial – there is a difference), and confirm with another source the extrapolated event date (birth/baptism – and here, too). An innocent mistake, but more common than you might think. Remember, close only counts in horseshoes and hand grenades. Some of those grenades find their way into online ancestry sites, where they create all sorts of problems for the too-trusting family genealogist. But more about that some other day.
Be a journalist. Before you commit to a fact, get confirmation from a second source.