It was reported that Abu Zarr Ghaffari said:

الدنيا ثلاث ساعات;ساعة مضت وساعة انت فيها وساعة اتدركها املا‘’

The world is only three hours: An hour that has past; an hour in which you are now; and an hour (to come) which you may or may not get. Thus, in reality, you have only an hour’’