Basically, the original batch of 2004 calendars were printed with a mistake (3 months are mis-dated). We are currently in the process of reprinting the calendars and will be shipping replacements to anyone who was sent an incorrect copy.
All new orders will receive a correct copy.
Please read here for more details:
http://ptenthusiasts.org/PTForums/announcement.php?f=37
That said, if you order before December 19th, you can still get your calendar before Christmas.