You have always learned that Lent commemorates the 40 days that Jesus spent praying in the desert before his public ministry. If, however, you actually count the days from Ash Wednesday to Easter Sunday, you'll realize there are actually 46 days! What? Yes, there are 46 days between Ash Wednesday and Easter. Because each Sunday of the year, however, is a grand celebration and commemoration of the resurrection of Jesus, we don't count them in the 40 days of penance. There are six Sundays between Ash Wednesday and Easter Sunday. So, by subtraction, we are left with 40 days.
Originally appeared in Knowing Our Catholic Faith