Mine isn't exactly a philosophical quote per se, it's a quote from a book I love that your quote reminded me of.
"He has to find more and better ways of occupying his time. His time, what a bankrupt idea, as if he's been given a box of time belonging to him alone, stuffed to the brim with hours and minutes that he can spend like money. Trouble is, the box has holes in it and the time is running out, no matter what he does with it." (From Oryx & Crake by Margaret Atwood)