When Was the Phrase Coined, "It's five o'clock somewhere"?

by Hennessy4

Is there any evidence for how long ago the phrase originated, "It's five o'clock somewhere"?

I'm wondering if the saying's popularity is due to it being a decade-old traditional phrase, or due to the Alan Jackson and Jimmy Buffett song, "It's Five O'Clock Somewhere".

jeffbell

In 1986 there was a book by Sylvia Cary titled It must be five o'clock somewhere, which is very close but not exactly the same phrase. I cannot find it used before that.

The Alan Jackson song came out in 2003.