The logic behind these special Sundays ranges from ludicrous fact embellishing to some solid reasons. I've heard songs sung in church that claimed the American Revolution was a struggle of good versus evil; that the colonies were fighting for religious freedom. This is not true. The Pilgrims and many others may have come to the New World to find religious freedom, but the colonies rebelled 150 years later purely for economic and political reasons. Nothing to do with religious freedom. Read the Declaration of Independence. Nothing about religious freedom in there.
Many people claim that we should celebrate America in churches because the nation was founded by Christians on Christian principles. This has some credence to it. Many of the founding fathers were deeply religious men, but the fact that they used flowery religious language does not mean that they were truly born again. It was standard back then to be religious. Everyone was. It was the culture of the day. Of course they talked about God, it just came with living in the deeply religious time right after the Great Awakening.
The fact is that there is nothing in the Bible about celebrating one's nation in church. Read the book of Acts; then read the rest of the New Testament. Nothing about the nation in corporate worship. The only responsibilities of the Christian to his nation are to pray for its leaders, obey the laws, and pay the taxes (please note that the founding fathers failed on the last two). Jesus said, "Give to Caesar what is Caesar's, and to God what is God's." The government has its own realm that it governs, and the church has its realm. Those two should stay separate.
There is one way to have a patriotic Sunday and stay within the principles the Bible lays out for worship. The goal of our existence and the goal of our worship is to glorify God. If at any time worship glorifies a man or country above God, it has become idol worship. We can thank God for we he has given us in our nation, as long as the focus stays on him.
I'm not against patriotism. I consider myself patriotic. I just don't think that someone has to be patriotic to be godly.