You Must Complete Your Flight by, at the Latest, Two Thousand and Twelve Years Ago

 Those pesky airline rules. 

I was trying to verify the policy for changing the date on a flight booked with frequent flyer miles and came across this helpful page. 

 You must complete your flight by Jan 01 of the year 0002.  

Not sure what kind of aircraft you would be on since the Wright brothers 1st flight wasn't until 1900, and according to Wikipedia, the hot air balloon wasn't much earlier

The brothers Joseph-Michel and Jacques-Etienne Montgolfier developed a hot air balloon in Annonay, Ardeche, France, and demonstrated it publicly on September 19, 1783 with an unmanned flight lasting 10 minutes.

Maybe carrier pigeon? 

Don't think the asterisk clears anything up. All it talks about is how much this change is going to cost you.  And I wonder what you should pay the airline change fees with?  May I suggest

Not sure how long this flight re-booking policy will be in effect, as the airlines change their rules all the time, so if you are going to check it out, do so soon.      united.com/reservation/flight/cancelAwardRebook.aspx