I used to be in the habit of praying the Chaplet of Divine Mercy every day at three PM. That was before I started working full time, when leisure moments were common. Now, with life as busy as it can get, I have gotten in the habit of setting the alarm on my cell phone to ring at three PM. Even if I am in the back of an ambulance tending to a patient, shopping in a store, or busy doing other things, this little reminder is all I need to spend a few moments meditating on the drops of Precious Blood that Jesus shed for us in His Divine Passion. I always offer the Precious Blood to God the Father, through the intercession of the Blessed Virgin Mary, in atonement for my sins and for the good of the whole Church every day at three o'clock. It only takes a few moments, but I believe its merits are many.
From the diary of St. Faustina:
1320 At three 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.
1572 I remind you my daughter that as often as you hear the clock strike the third hour, immerse yourself completely in My Mercy, adoring and glorifying it; invoke its omnipotence for the whole world, and particularly for poor sinners; for at that moment Mercy was opened wide for every soul.