Driving around mid-town Manhattan at 3 am. Turn into parking garage with big “Open 24 Hours” sign. Closed. Back-up, avoiding a collision with one of the many pedestrians walking around on the surprisingly lively streets. Drive one block. Look before turning into second garage with big “Open 24 Hours” sign. Closed. Repeat with a third. Finally, find a forth that’s open.
Ugh.
Ben Galbraith 
Perhaps it means 24 hours per week.
Walking in the prescnee of giants here. Cool thinking all around!