It was reported that Abu Zarr Ghaffari (Radiallahu Anhu) 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”