How often does the US Congress meet?

Congress Meetings

Congress has to meet at least twice in their two year term, at least once a year.

Article I, Section IV of the Constitution states that Congress meets once a year in December; however, transportation technology has advanced so that they are able to meet more than one time per year if necessary.

The 20th Amendment, Section II of the Constitution changes the meeting date to the 3rd of January, and allows the same frequency of meetings as stated prior.
Congress is only required to have one session per year, and the length can be whatever is decided by Congress itself. Each new Congress begins on or after January 3. They are required to meet every other year