On occasion, I will come across research done by an individual and will find errors in the dates.  There are some basic math calculations that need to be done when checking your genealogical research for accuracy.  One of the big ones is: were the parents even old enough to have children at the date of their first child’s birth.  Another is, was the father alive at the time of conception (this is one calculation that disproved a long assumed connection in my own family tree – the math just did not add up).

When a date or time period does not work, take a look at the sources for the dates.  For example, not all baptisms occurred at birth, there can be many years in between the two events.  Watch your assumptions…

Many genealogy software packages have calculation pop-up warnings.  I recommend that you keep those pop-ups on, not only for the math issue but also for the typo issue (no more 1880s showing up as 1980s).

Barbara Renick’s book Genealogy 101 looks at Date Dilemma and the importance of calculating dates.