Inauguration Day

Inauguration Day is a quadrennial holiday that is celebrated on January 20 every 4th year since 1937. Prior to the ratification of the Twentieth Amendment, Inauguration Day was on March 4 every 4th year from 1793 to 1933. This year, Inauguration Day was on a Wednesday.

Past inaugurations
The information below is from the Wikipedia article United States presidential inauguration#List of inauguration ceremonies.