Ash Wednesday is determined by counting back 40 days from Easter, excluding Sundays. Ash Wednesday not only initiates the season of Lent, but carries a three-fold emphasis – meditating on our mortality, acknowledging our sinfulness, and focusing on our need of a savior. Ash Wednesday, then, is preparation time for centering our hearts on the beauty and significance of our dying and rising with Christ. The imposition of ashes is often customary on Ash Wednesday since ashes (dust) symbolize our frailty/death, sadness/mourning, and repentance.
Some possible Psalms to use on Ash Wednesday: