National Comic Book Day is a holiday similar to Free Comic Book Day, with a few key differences:

-It is in September.
-There is no industry support.
-You do not get a free comic book.
-It appears to have no founders.
-It isn't celebrated or observed anywhere.

In fact, some of the top search results for this holiday include a closed Facebook event invitation and a web page which produces a "known attack site" warning in Firefox.

Anyone who tells you this is an actual holiday cannot be trusted. Never rely on this person to provide you with accurate information, because it will be clear to you they are lying or horribly misinformed about almost any subject on which they speak.

This holiday sucks, and its authenticity needs to be challenged anywhere it is found. Choose to celebrate nerdery with Free Comic Book Day, and abandon false observances.