I just checked, and whatever it was is unique(ish) to you - a couple of other member's (one old, one new) I checked had normal settings.

I must be special. Seems my date of birth changed from 19th Feb 1974 to 20th Feb 1974 too. Had to fix that the other day :)

That's weird. I went to check your DOB and it was set to 15th. I reset to 19th now, and it is showing 19th as your user, my user, and also in the database. I was thinking it may be some issue with timezones, but if I explicitly set using and viewing using both negative and positive timezones it seems okay also.

May be an issue with our workaround to Firefox's lack of HTML5 date input. I'll check that too.

Hmm, no, seems fine on Firefox also.

Well that's kinda weird then. Obviously I have no useful input on this, other than I definitely set it to the 19th when I noticed it had decided to become the 20th.