Green’s Dictionary of Slang

(S.Afr.) free time.

1966		L.G. Berger Where’s the Madam? 183: The watchboy supplied by Norman’s firm hadn’t come back from his ’off which is the native abbreviation for ‘day off’.
1971		informant in DSAE (1996).
1980		J. Cock Maids and Madams 27: The only time she sees her children is during her ‘off’ on Sunday afternoons.
1987		Learn and Teach 13: Agnes Vilakazi of Johannesburg [...] said, ‘We do not get nice “offs”. We don’t get week-ends and holidays off. This is not right.’ [DSAE].