Final answer:
Originally, Congress was to meet on the first Monday in December each year as stipulated by the Constitution. The 20th Amendment, passed in 1933, changed this to noon on the 3rd day of January unless otherwise provided by law.
Step-by-step explanation:
The day originally specified for Congress to assemble each year has changed over time. Initially, according to the Constitution, Congress was to meet once in every Year, and this meeting was to be on the first Monday in December. However, the passage of the 20th Amendment in 1933 changed this date. Now, Section 2 of the 20th Amendment specifies that Congress shall assemble at least once in every year, and such meeting shall begin at noon on the 3d day of January, unless they shall by law appoint a different day. This adjustment aligned the assembly of Congress closer to the start of the calendar year and after the newly elected members have been sworn into office.