National Day of Reason Date in the current year: May 2, 2024

National Day of Prayer was created for all Americans to turn to God, gather together and pray for peace and prosperity of the nation. However, not all Americans consider themselves to be members of any religion and thus they can't pray. National Day of Reason was created only for them to have a reason to celebrate. However, this secular holiday also raises public awareness of the threat to religious liberty posed by American government intrusion into the private sphere of worship.

National Day of Reason was created in 2003 by the American Humanist Association. In 2005 the observance was strongly advocated by the Center for Atheism and they marked it with blood donation. During the next years the popularity of this observance grew. In 2011 and 2012 the representative Pete Stark supported the proclamation of National Day of Reason in the House of Representatives and the resolution to honor this day was introduced in the U.S. House of Representatives.

Different events are organized by many associations on National Day of Reason. These events vary from blood donations and food drives to secular celebrations as alternatives to National Day of Prayer. Many individuals protest observance of National Day of Prayer.