Final answer:
Congress must meet at least once a year according to the Constitution, with the first meeting of each year set to begin at noon on January 3rd due to the 20th Amendment. Prior to this amendment, the required meeting date was the first Monday in December. Congress may hold additional sessions as needed.
Step-by-step explanation:
The United States Congress is required to meet at least once every year. This mandate is established by the Constitution to ensure that Congress performs its legislative duties in a regular manner. The 20th Amendment, passed in 1933, specifies that the first meeting of Congress must begin at noon on January 3rd of each year, unless Congress by law appoints a different day. Prior to this amendment, Congress was required to meet on the first Monday in December as stated in the original text of the Constitution.
Congress has the authority to determine its own schedule beyond the constitutional requirement for at least one session per year. Regular sessions and any potential special sessions beyond the constitutionally mandated sessions are at the discretion of Congressional leadership and the needs of the nation. It is during these sessions that Congress conducts the nation's legislative business, including discussions and votes which are recorded and published, with certain exceptions for privacy as stated in the Constitution.