Saint Faustina recorded these words of Our Lord in her diary: "At 3 O’clock, implore My mercy, especially for sinners; and, if only for a brief moment, immerse yourself in My passion, particularly in My abandonment at the moment of agony. This is the hour of great mercy for the whole world. I will allow you to enter into My mortal sorrow. In this hour, I will refuse nothing to the soul that makes a request of Me in virtue of My Passion."
From this has come the practice of reciting the Divine Mercy Chaplet every day at 3 P.M.