Time flows like the water through your fingers. Probably, time means to economics more than anything else.

"The supply of time is totally inelastic. No matter how high the demand, the supply will not go up. There is no price for it and no marginal utility curve for it. Moreover, time is totally perishable and cannot be stored. Yesterday's time is gone forever and will never come back. Time is, therefore, always in exceedingly short supply."

Peter F. Druker "Effective executive"