in reply to I misspoke...
in thread File Age in Seconds ? (need more handholding)

perl -le "print(time - ( stat(q[file.txt]) )[9])"
or perldoc -f stat

Ted
--
"That which we persist in doing becomes easier, not that the task itself has become easier, but that our ability to perform it has improved."
  --Ralph Waldo Emerson