Join Date: Apr 2009
Location: Bye Delta
Programs: AA EXP, UA Silver, HH Diamond, IHG Plat, Hyatt Plat, Marriott Titanium, Nat'l EE, Avis PC, Hertz PC
Posts: 16,633
That's my understanding of the language. It says it is valid for one day. To me, that means one full day, not a single visit, especially when coupled with the language that extends the validity to a second day if your journey contains overnight flights.
When I used day passes (and admittedly it's been perhaps 2-3 years), they never took them at the first club, they just stamped it and handed it back. Maybe they scanned it too. But they never kept it.