So, giving up something which is not good for us, as well as spending time on "quiet reflection and contemplation".... don't we as Buddhists try to practice these same things everyday? Well, nobody is perfect, we all have our vices, and if you were to be perfect, well...you'd be a Buddha.
Now, I respect the observation of Lent if you're going to give up something to totally rid your life of it (i.e. smoking, drinking, sexual misconduct, etc). But many people I speak to often say, "I'm giving up chocolate" or "I'm giving up shopping" for forty days. This kind of boggles me. Why only forty days? Why wouldn't you want to give up a negative aspect of your life or character to get rid of it permanently?
Or better yet, practice "giving up" all year round from year to year?
"Jesus retreated into the wilderness, where he fasted for forty days, and was tempted by the devil (Matthew 4:1-2, Mark 1:12-13, Luke 4:1-2). He overcame all three of Satan's temptations by citing scripture to the devil, at which point the devil left him, angels ministered to Jesus, and he began his ministry. Jesus further said that his disciples should fast "when the bridegroom shall be taken from them" (Matthew 9:15), a reference to his Passion. Since, presumably, the Apostles fasted as they mourned the death of Jesus, Christians have traditionally fasted during the annual commemoration of his burial."
This passage reminds me very much of when Siddhartha (The Buddha) was meditating under the Bodhi tree and being tempted by Mara. And this biblical passage, I believe, is to teach those who faithfully follow Christ, to resist all things worldly, day to day, year to year. As the passage from James 4:4 reads, "A friend of the world is an enemy to God." (Speaking of all worldly things and desires).
In the end, why not use the time to better yourself, or better the world?