Popup calendar thinks it is 1988

This should be funny, but it's preventing edits through admin. Check out the attached screen caps. First is showing that this is a leap year and March 1st isn't until Tuesday. The second one shows what happens after I clicked on March 31st -- apparently I'm back in 1988! Anyone else dealing/dealt with/fixed this?

It used to say "1969." I wouldn't be complaining, as this seems like an improvement to me.