I don't know if this is a planned behavior, so I thought I'd tell you.
Because I got bored, I decided to change my birthdate to the current date, minus about 470 some years, just to see if my name got up there and what number would be by it.
But I noticed if put the date even as early as 1900 flat, something internal switches it around to 12/31/69. A date in the '50s DID work, so that's probably not the upper limit and I assume you have one to stop such sillyness, but I thought you might want to know.
And now you do. Oh wow have the Lemonheads kicked in.
I ran into a weird sort of thing with the birthday thing. I put in 1982, as it was the year I was born and all, but left the month and day blank, and now my Profile lists me being born on November 30, 1981.
OK, trying again with the same thing gives me the same result.
Trying again but leaving 1981 as the year gives me November 30, 1980.
Hey, I wonder what happens when I input only a month...Trying November in the Month column means I was born on October 31, 2000. Interesting...Trying it with December gives me November 30, 2000, so I'm guessing the form is [Last Day of Previous Month], 2000.
Now then, Month and Year blank, Let's make the Day the 4th. December 4, 1999. Well, that one kinda held up. The Standard form there seems to be December [Day], 1999.
Putting in 2 factors seems to turn out OK as well.
Oh well, just a silly little glitchy thing, I guess. Back to the full, actual date.
It was worse a few days ago. Apparently the default date for NULL was Dec 31, 1969. Everyone who left it blank showed up on the 31st... Adam fixed that already so it won't happen next year.