Green’s Dictionary of Slang

1. (US prison) the date of one’s release as given by a parole board (the day on which one ‘gets up’ in prison but goes to bed free).

1918		H. Simon ‘Prison Dict.’ in AS VIII:3 (1933) 27/1: GET-UP. The morning of one’s release. Boy, I only got sixty-seven more days an’ a get-up — I’m gettin’ short fer fair!
1927		H. Yenne ‘Prison Lingo’ in AS II.6 281: Roll over, or a get up — The last night before being released.
1932		L.E. Lawes Twenty Thousand Years in Sing Sing 244: He is going home soon [...] So many days and a ‘get up’.
1950		Goldin et al. DAUL 56/1: Dancing. (P) Nervous with anticipation [...] ‘Three days and a get-up (day of release)! Man, I’m dancing now!’.
1983		R. Klein Jailhouse Jargon and Street Sl. [unpub. ms.].
1999		E. Bunker Mr Blue 193: ‘How much you got left?’ ‘Sixty-two days and a get up.’.

2. an amount of heroin, used in the morning to prevent withdrawal symptons; also attrib.

1967		Maurer & Vogel Narcotics and Narcotic Addiction (3rd edn).
1975		Hardy & Cull Drug Lang. and Lore.
1981		E. Bunker Little Boy Blue (1995) 283: I thought you had a getup fix.
1990		(con. 1930s–60s) H. Huncke Guilty of Everything (1998) 75: That was my get-up in the morning [...] He’d have my shot all ready, tie me up, and I’d just sit there and play.
1999		E. Bunker Mr Blue 252: I don’t have anything for a getup. I’m gonna be sick in the morning.