Time and Tide waits for no man. A familiar saying from the days of sailing ships when tides determined departure times. Supposedly a quote as early as the 14th century. Basically means if you've got something important to do, don't procrastinate, because neither time nor tide will wait for you.
Man 1 : We have to wake up early tomorrow for fishing
Man 2 : Why do we have to wake up so early?
Man 1 : By Ebb and flow! The largest fish hang around in the mornings