1
general::
One's time is a valuable commodity, as in I can't stay home and wait any longer; time is money, you know. This proverbial term goes back to one first recorded in 1572, time is precious, in a discourse on usury.
American Heritage Idioms
2
general::
Phrase(s): Time is money.
(My) time is valuable, so don’t waste it. • I can’t afford to spend a lot of time standing here talking. Time is money, you know! • People who keep saying time is money may be working too hard.
McGrawhill's American Idioms And Phrasal Verbs