Wednesday, September 11th, 2019 marks the 18 year anniversary of the 9/11 terrorist attacks on the World Trade Center in New York City, the Pentagon, and United Airlines Flight 93 which crashed in suburban Pennsylvania. Patriot Day serves as a remembrance of the lives lost on that September morning.

By a joint resolution approved 12/18/2001, (Public Law 107-89) has designated September 11th  of each year as "Patriot Day" which also directs the flags be lowered to half-staff for the entire day on September 11.

A section of the law is below:  

''144. Patriot Day''(a) DESIGNATION.-September 11 is Patriot Day.''(b) PROCLAMATION.-The President is requested to issue each year a proclamation calling on- 

''(1) State and local governments and the people of the United States to observe Patriot Day with appropriate programs and activities;

''(2) all departments, agencies, and instrumentalities of the United States and interested organizations and individuals to display the flag of the United States at halfstaff on Patriot Day in honor of the individuals who lost their lives as a result of the terrorist attacks against the United States that occurred on September 11, 2001; and' 

'(3) the people of the United States to observe a moment of silence on Patriot Day in honor of the individuals who lost their lives as a result of the terrorist attacks against the United States that occurred on September 11, 2001.''.