Milestone Due Date Problem On Invalid Form Data

You can replicate this problem easily by creating a new Milestone and then clicking the "Add Milestone" button without properly filling in one of the fields. When the form comes back with the warning about which field you've improperly filled out, the due date will be January 1, 1970. Since the due date year dropdown only holds about two decades, you cannot possibly select the current year. At 1970, the dropdown shows a list of years from 1960 to 1980.

If you don't want to recreate the Milestone from scratch, you need to come back and edit the Milestone a few times to get the year dropdown to show the current year. The problem could be fixed either by allowing the due date year dropdown to hold more than 10 years (or whatever amount) or fix the bad date (I think it equates to 0 in PHP when that's happening).