Green’s Dictionary of Slang

1. (orig. US) an office worker, thus any ‘ordinary’ person.

[1908		Sun. Times (Perth) 29 Mar. 4/7: A Civil Servant invented the united Australia puzzle. Now we know how the ten-to-fourers manage to kill time!].
1967		Oz 5 n.p.: This bizarre cult of grey, short-haired nine-to-fivers is sweeping the country.
1978		H. Selby Jr Requiem for a Dream (1987) 78: The nine to fivers, the brown baggers, the strap hangers, the working stiffs.
1986		R. Condon Prizzi’s Family 115: I am a nine-to-fiver just like anybody else. I kiss you goodbye in the morning and I go out. Then I come home and we do whatever you wanna do.
1990		Tupper & Wortley Aus. Prison Sl. Gloss. 🌐 Nine to fivers. Civilians. Has derisory overtones.
2005		J. Daw Epoch Dawn 57: He had never been one for being a nine-to-fiver. It wasn’t just the routine that he couldn’t do, but that the timing seemed all wrong.
2018		J.-P. Jordan Joys of War 15: You can dress it up all you want for the 9 to 5ers watching the evening news but war is war, my friend .

2. an office job.

1975		L. Feather From Satchmo to Miles 168: If I didn’t have this nine-to-fiver, I’d be up at Frank E. Campbell’s paying my respects.
2004		E. Avedissian Young Republican’s Hbk 159: [...] busily laboring all day at your nine-to-fiver before retiring for a few drinks and a long ride after work to get home.