"Spend the afternoon. You can't take it with you"

"Spend the afternoon.  You can't take it with you" - Annie Dillard (Writer)

In case you don't catch on, this is a metaphor of sorts.  You can not literally use the afternoon as money. 

Just, live your days.  Because once the day is over, it's gone.  You can't get it back.  You can't save time like money and use it later.  You either use it now or let is slip away.  Your choice.