When did golden oldies become oldies?

The subject line pretty much sums up the question. Please help.

I first heard the term when they started publishing the “Oldies But Goodies” albums around 1963. The were collections of 50’s rock & roll, which at the time was only about 10 years old at the most.

Golden oldies were referred to as such back in the 1950s, and there is a song from that era that already has golden oldies in the lyrics although there are too many “Golden Oldies” sites to find it on Google.

The term still tends to refer to 50s songs, with 60s tunes merely being oldies. It was that way even in the 60s. I can’t give any exact date, though. I started listening to rock in 1963, if that’s any indication.

The NY ‘oldies’ station, which played fifties songs in my childhood (eighties) and sixties songs during my teens (nineties), has within the last year or so started playing lots and lots of disco. When did seventies music become ‘oldies’? Rock from the seventies has been ‘classic rock’ for a while, but I’ve never heard it referred to as oldies.