poet’s day, n. — Green’s Dictionary of Slang

poet’s day n.

[abbr. piss off early, tomorrow’s Saturday]

Friday.

1989		J. Morton Lowspeak.
1999		I. Rankin Dead Souls 281: Off you go now. POETS day, you know, weekend coming up.
2002		A. Dundes ‘Much Ado about “Sweet Bugger All”’ in Folklore Vol. 113 n.p.: The popularity of the ‘Piss off’ idiom in England is suggested by the dismissive acronymic POETS, standing for ‘Piss Off Early, Tomorrow’s Saturday.’.
2006		I. Rankin Naming of the Dead (2007) 403: ‘POETS day,’ he reminded Siobhan. ‘Piss Off Eary, Tomorrow’s Saturday,’ she recited.
2018		‘Isballa at asstr.org 28 Feb. 🌐 Johnny got home at four-thirty, POETS day, Piss Off Early, Tomorrow’s Saturday!