When did we quit calling Independence Day just that?

When did it start being referred to as only, "The Fourth of July" or simply, "The Fourth?" I made a resolution a few years back to only refer to the holiday by its proper name. You'd be surprised how many people have no idea what I was talking about. Especially youth. Just another cheapening of our society. A calendar day vs. an actual name. Soon Christmas will be just, "December 25th"