Knowledge of a Date

This post includes thoughts…without necessarily answers.

If my daughter tells someone her date of birth, she is a secondary source of that date. She has no first hand knowledge of her date of birth. It doesn’t mean that she gives someone the wrong date of birth, just that her knowledge of it comes (most likely) from her parents or from her certified copy of her birth certificate.

If I tell someone that today is my daughter’s 21st birthday (which it isn’t, but pretend that it is), is that secondary? I was present at the birth, but if I say it or write it down 21 years later is that record primary or secondary? If I write it down with a month of her birth, that probably would be considered primary. But what about 21 years after the fact, even if I had first hand knowledge of the event? And, 21 years later when I say it’s her birthday, did I say it totally from memory or did I refer to her birth certificate (or some other record) first–just to make certain?