Are Holy Days of Obligation Man Made Religious Traditions?

Today is August 15th 2011.  For us Catholics, it is also the Solemnity of the Assumption of the Blessed Virgin Mary - one of the many Holy Days of Obligation.  Granted, there are few Protestants these days who carry a high regard for Mary (unlike their "Fathers of the Faith" including Martin Luther and John Calvin) let alone believe that she was assumed into Heaven like Elijah, but that is not really the topic of this post.

During a conversation that my wife was having with her friends regarding the "abrogation" of this Holy Day of Obligation, a Non-Catholic friend of ours who was also part of the conversation made the following comment (paraphrasing):

"I don't follow any man-made religion.  Every day is a holy day for me".

Obviously, he makes a very good point.  We should treat every day as a gift from our Creator, and therefore should regard it as Holy.  However, the comment regarding a man-made religion made me question if, in fact, Holy Days of Obligation are a man-made tradition.  So....are they part of a man-made tradition?  Before I answer that question I think we have to first understand what a man-made traditions are.  

If you have been a Catholic for more than ten minutes and if you have engaged in any kind of religious conversation with Protestants, sooner or later, they are going to bring up this concept of a man-made tradition.  What are man-made traditions?  Or better known as traditions of men?  It is a direct reference to Scripture.  In Mark 7:1-13 we witness an exchange between the Pharisees and Jesus Christ where Jesus ultimately tells the Pharisees:

Neglecting the commandment of God, you hold to the tradition of men (Mark 7:8).

Jesus is saying that instead of following God, they are following the teachings of men.  The Pharisees are holding their own practices and beliefs higher than God's.  This is ultimately the same accusation that Protestants make against the Catholic Church  They are basically saying that we are holding to the traditions of man instead of the Teachings of God.  While many Protestants may not realize it, this is a complete insult against the Catholic Faith.

Do you not think so?  Maybe you think I am taking this statement too much to heart.  If you think so, then I welcome you to try a little experiment.  Next time you are in a conversation with a Protestant friend, and they mention to you something along the lines of their church has asked every member to fast on a certain day, or devote themselves to prayer for a certain hour of the week, just respond to them in the same fashion.  Say something along the lines of, "I am not going to follow any man-made tradition.  Every day should be dedicated for prayer".  Do you think that they will be offended?  I am sure they would.

Are Holy Days of Obligation a man-made tradition?  Of course not.  How do I know this?  Because Jesus Christ told me Himself that he was going to create a Church, and of that Church, the Gates of Hell would never prevail.  Jesus also said that he was going to give that Church the Holy Spirit to lead into all areas of truth.  Since the Catholic Church is the only Church that I have been able to recognize that has existed since the Apostles, and I am utterly convinced that the Gates of Hell has attempted to prevail against it and yet it still has not succeeded (nor will it ever), I have to believe that the traditions / teachings of this Church are exactly what Jesus Christ said that they would be:

I will give you the keys of the kingdom of heaven; and whatever you bind on earth shall have been bound in heaven, and whatever you loose on earth shall have been loosed in heaven. (Matt 16:18)

If the Church asks the faithful to gather together, celebrate, and pray during certain days of the year, Holy Days of Obligation (including Sunday, I might add), how can it be man-made traditions?