N.C. Const. art. II, § 11

Sessions. (1) Regular Sessions. The General Assembly shall meet in regular session in 1973 and every two years thereafter on the day prescribed by law. Neither house shall proceed upon public business unless a majority of all of its members are actually present . (2) Extra sessions on legislative call. The President of the Senate and the Speaker of the House of Representatives shall convene the General Assembly in extra session by their joint proclamation upon receipt by the President of the Senate of written requests therefor signed by three-fifths of all the members of the Senate and upon receipt by the Speaker of the House of Representatives of written requests therefor signed by three-fifths of all the members of the House of Representatives.