Well, first of all, it should be “Which day is ‘MORE’ important?” Use the comparative degree when comparing two subjects. Most all of the documentation for the lost Pentagon money (what documentation there was, that is, was destroyed in the twin-towers demolishment — oh so convenient (not that anything would have been done about it anyway). It’s like so many of the Congressional “hearings” — they serve as photo-ops and providing an impression to the public that their government is hard at work uncovering dastardly deeds; nothing ever proceeds from these hearings.
alternativebyfritz 
Well, first of all, it should be “Which day is ‘MORE’ important?” Use the comparative degree when comparing two subjects. Most all of the documentation for the lost Pentagon money (what documentation there was, that is, was destroyed in the twin-towers demolishment — oh so convenient (not that anything would have been done about it anyway). It’s like so many of the Congressional “hearings” — they serve as photo-ops and providing an impression to the public that their government is hard at work uncovering dastardly deeds; nothing ever proceeds from these hearings.