Pretty much every day of the year is some kind of crazy day honoring something. Sometimes they're things worth honoring, sometimes it's stuff like "Upsy Daisy Day", where people are "encouraged to face the day positively", and other crap like that.
How about "Second Half of the Year Day". Basically just July 1st, because no one could come up with anything else. Seriously.
Today is a great day for celebrating, since it's "National Hamburger Day"!