The Optional Memorial of St. Faustina Kowalska honours the Polish religious sister whose life and writings helped spread devotion to the Divine Mercy of Christ. Through her spiritual diary, she recorded a message centred on trust in God’s mercy, forgiveness and compassionate love.

St. Faustina died in Kraków in 1938 at the age of thirty-three and was canonized by St. John Paul II in 2000. Her witness became closely associated with Divine Mercy Sunday and with the image of Christ bearing rays of red and pale light.