I think that Darren Lynn Bousman just has a thing for making movies centered around specific dates. Cinco de Mayo is his newest movie, with Mother's Day and 11-11-11 also in his repertoire.
Cinco de Mayo is a horror movie centered around a group of illegal Mexican immigrants trying to cross the Mexican-Arizona border when things go very awry. The trailer itself does some pretty annoying quick-editing stuff, but otherwise looks okay. Cinco de Mayo will open May 5th, 2013 as you may have guessed.