Totally can relate!!! My ds, who by the way, tested not to be gifted, has been able to tell us (since hes been around age 5 or so) what random day falls on what month/date in say....I don't know, the year 2013, 2020, etc...??? And the kid gets it right every single time!!! It blows my husband and I away. Ds11 has always had an amazing memory for dates, facts, etc...But oddly enough, not tested gifted??? He's the one I would have bet money on...Hit all the Ruf level 3/4's...Strange. Now that's another story...lol
There's an actual term for someone who can do this with dates. I was watching a special on it once, about twins who loved Dick Clark. Can't recall the other "issues" that the girls had been diagnosed with, but you could ask them what day 3/12/1809 was on, and they would know, not even being alive them. I'll have to research what it's called.
Savants... but it says that the person/child would have a disorder too... so nevermind.