President Barack Obama, First Lady Michelle Obama and White House staff observe a moment of silence on September 11, 2009.

President George W. Bush and Vice President Dick Cheney on September 11, 2004 lead a moment of silence on the South Lawn with White House staff and families of victims of 9/11.

Patriot Day is a day of remembrance in the United States. It happens on September 11 of each year. It remembers the 2,977 killed in the September 11, 2001 attacks. Most Americans call this day "Nine-Eleven (9/11)," "September Eleventh," or something similar.