2 Chronicles 29:31 - "Hezekiah said, Now ye have consecrated yourselves unto the LORD, come near & bring sacrifices & thank offerings into the house of the LORD. And the congregation brought in sacrifices & thank offerings; & as many as were of a free heart burnt offerings." - Thanksgiving is only worth something if you do it willingly, not because it's that time of year. God is worthy to be praised ALL the time.