When you load up a game page for editing that has a fuzzy First Release Date with a quarter specified, the editing form will increase the quarter specified by one. Thus if you then save the page you will have changed the release date for the title without knowing.
A good example is Axiom Verge. Release date is currently Q1 2015. Load it up in the editor, it becomes Q2 2015. Another is The Legend of Doodle, where Q2 becomes Q3, or Curses 'N Chaos where Q4 becomes an empty field (and that Q4 seems another case of the bug, as I believe the game should be Q3).
Tested on Firefox 29 on Windows 8.1 and Xubuntu 14.04, and on Chrome 34.0.1847.116 Xubuntu 14.04.