Question: The second inauguration of Ronald Reagan as President of the United States was held privately on Sunday, which date, in the Grand Foyer of the White House, and publicly the following day, January 21, 1985 at the United States Capitol in Washington, D.C., the United States Capitol, often called the Capitol Building, is the home of the United States Congress, and the seat of the legislative branch of the U.S. federal government?

Context paragraphs:
13th United States Congress: The Thirteenth United States Congress was a meeting of the legislative branch of the United States federal government, consisting of the United States Senate and the United States House of Representatives.  It met in Washington, D.C. from March 4, 1813, to March 4, 1815, during the fifth and sixth years of James Madison's presidency.  The apportionment of seats in the House of Representatives was based on the Third Census of the United States in 1810.  Both chambers had a Democratic-Republican majority.  The first two sessions were held at the Capitol building while the third, convened after the Burning of Washington, took place in the First Patent Building.

United States Capitol: The United States Capitol, often called the Capitol Building, is the home of the United States Congress, and the seat of the legislative branch of the U.S. federal government.  It sits atop Capitol Hill at the eastern end of the National Mall in Washington, D.C. Though not at the geographic center of the Federal District, the Capitol forms the origin point for the District's street-numbering system and the District's four quadrants.

Inauguration of Jimmy Carter: The Inauguration of Jimmy Carter as the 39th President of the United States was held on Thursday, January 20, 1977, on the East Portico of the United States Capitol in Washington D.C..  The inauguration marked the commencement of the only four-year term of Jimmy Carter as President and of Walter Mondale as Vice President.  Chief Justice Warren E. Burger administered the presidential oath of office to Carter, and Speaker of the House Tip O'Neill administered the vice presidential oath of office to Mondale.  This was the last inauguration held on the East Portico of the Capitol building to date.

Second inauguration of Bill Clinton: The second inauguration of Bill Clinton as President of the United States was held on Monday, January 20, 1997 on the West Front of the United States Capitol Building in Washington, D.C..  The inauguration marked the commencement of the second four-year term of Bill Clinton as President and Al Gore as Vice President.  This was the last presidential inauguration to take place in the 20th century, and the first to be streamed live on the internet.

First inauguration of Ronald Reagan: The first inauguration of Ronald Reagan as the 40th President of the United States was held on Tuesday, January 20, 1981, on the West Front of the United States Capitol in Washington, D.C..  This was the first inauguration to be held on the building's west side.  The inauguration marked the commencement of the first four-year term of Ronald Reagan as President and of George H. W. Bush as Vice President.  Chief Justice Warren E. Burger administered the presidential oath of office to Reagan, who placed his hand upon a family Bible given to him by his mother, open to .  Associate Justice Potter Stewart administered the vice presidential oath to Bush.

Second inauguration of Ronald Reagan: The second inauguration of Ronald Reagan as President of the United States was held privately on Sunday, January 20, 1985 in the Grand Foyer of the White House, and publicly the following day, January 21, 1985 at the United States Capitol in Washington, D.C. The inauguration marked the commencement of the second four-year term of Ronald Reagan as President and of George H. W. Bush as Vice President.

Second inauguration of Dwight D. Eisenhower: The second inauguration of Dwight D. Eisenhower as President of the United States was held privately on Sunday, January 20, 1957 and publicly the following day, January 21, 1957.  The inauguration marked the commencement of the second four-year term of Dwight D. Eisenhower as President and Richard Nixon as Vice President.  Chief Justice Earl Warren administered the Oath of office.

Second inauguration of Barack Obama: The second inauguration of Barack Obama as President of the United States, marked the commencement of the second term of Barack Obama as President and Joe Biden as Vice President.  A private swearing-in ceremony took place on Sunday, January 20, 2013 in the Blue Room of the White House.  A public inauguration ceremony took place on Monday, January 21, 2013, at the United States Capitol building.

Second inauguration of Woodrow Wilson: The second inauguration of Woodrow Wilson as President of the United States was held privately on Sunday, March 4, 1917 and publicly on Saturday, March 5, 1917, at the east portico of the United States Capitol in Washington, D.C..  The inauguration marked the commencement of the second four-year term of Woodrow Wilson as President and of Thomas R. Marshall as Vice President.  Chief Justice Edward D. White administered the presidential oath of office to Wilson

98th United States Congress: The Ninety-eighth United States Congress was a meeting of the legislative branch of the United States federal government, composed of the United States Senate and the United States House of Representatives.  It met in Washington, D.C. from January 3, 1983, to January 3, 1985, during the third and fourth years of Ronald Reagan's presidency.  The apportionment of seats in the House of Representatives was based on the 1980 U.S. Census.  The Republicans controlled the Senate, while the Democrats controlled the House of Representatives.

Supporting paragraphs: Second inauguration of Ronald Reagan United States Capitol
Answer: January 20, 1985