Green’s Dictionary of Slang

working in a routine job.

[1915		Van Loan ‘Sporting Doctor’ in Taking the Count 56: I’m going to be a regular nine-to-twelve and two-to-five doctor for a change].
1961		H.S. Thompson in Proud Highway (1997) 303: ‘Nine-to-five types’ with dark suits and chic dates.
1977		C. McFadden Serial 22: Cut out the nine-to-five shit.
1989		Pileggi & Scorsese Goodfellas [film script] 46: We weren’t married to nine-to-five guys.
1996		(con. 1949) G. Pelecanos Big Blowdown (1999) 293: You can leave that nine-to-five bullshit to your buddy Pericles and all those other altar boys.
2000		P. Beatty Tuff 236: I see you goin’ to church Sunday morning, walking your kids home from school. Y’all the normal nine-to-five people.