Please see the FAQ section of the Contribution Bible:

Person X was credited on TV series Y, but Y premiered years before they were born!

All television credits on a person profile are assigned the year that the series premiered. For certain long-running tv content, such as The Oscars, that may mean that some credits are assigned a year that is before the person was born. If you click through to view the credits, you will find that the person is typically credited on episodes that are years/decades after the premiere, such as here.