National Day of Prayer Unconstitutional

I would like someone to please show me an article or an amendment in the Constitution that addresses the constitutionality of a national day of prayer. US District Judge Barbara Crabb wrote in her decision, "In this instance, the government has taken sides on a matter that must be left to individual conscience." (read the whole article at LifeSiteNews.com) The government is not knocking down doors and forcing people to pray a national prayer. They are allowing for a day that recognizes religious freedom. What is unconstitutional about that? Was that no small part of the basis for our founding as a nation?

Another instance of Feminine Genius FAIL!