I never heard it before. It's unusual. I'd never say it that way. It's close to being "wrong." However, if I heard it, I'd understand it and it probably wouldn't bother me.
The people in this video are speaking in a very relaxed, unprepared, spontaneous way, goofing around and having fun, and obviously not thinking very carefully about speaking model English. It is common to write the date in either of two styles, "July 1, 2015" and "July 1st, 2015." If I weren't thinking much about what I was saying, and if someone told me the date _in writing,_ I might just deliver it the same way it had appeared in writing.
The most common way to say it aloud would be "July the First" or "July First." The other order is preserved in the customary way we say the date of Independence Day, which is usually "the Fourth of July." It's common, but old-fashioned.
It is fairly common to read it aloud numerically, especially if we are dictating a date and including the year: "six, one, twenty-fifteen." Hence September 11th, 2001 becomes "nine-eleven," the customary way to refer to the date of the destruction of the World Trade Center in New York.