If Lent is 40 days, why do we not count Sundays? Are Sundays included in Lent? The answer is no Sundays are not included in Lent.
Jesus's first disciples followed the Book of Genesis. Saturday was the day of rest when God created the world. People who are Jewish still have their Sabbath on Saturdays.
Christians changed the day to Sunday because Jesus Christ rose from the dead on a Sunday. The original disciples called the apostles noted the Resurrection as a brand new period in life. So Sunday became the Christian Sabbath day so to speak.
Each Sunday became a day to celebrate and rejoice that Jesus Christ rose and is the Son of God. Christians changed Saturday to Sunday for the day of rest. Penance of any kind or fasting would be forbidden.
The 40 days of Lent represent when Jesus fasted in the desert for forty days before publicly starting His ministry. Sundays do not count because of no fasting or penance. Therefore, Lent had to be made into six full weeks plus four extra days.
The four extra days are Ash Wednesday, Thursday, Friday and Saturday during that week. If you do the math, you will see that there are exactly 40 days during Lent. Sundays are truly a day of rest.