This puzzle appeared in Microsoft Puzzle Hunt 15, whose theme was movies.
That event was modular in that each author wrote a module consisting of a few
puzzles and a metapuzzle.
The theme of my module was sequels.
Each date indicates how many letters its headline's answer is, and which one of those letters is important. For instance, "May 12" means "This headline clues something 12 letters long, and the 5th of those 12 letters will help form the final clue phrase."