Patriot Day is an annual observance on September 11 to remember those who were injured or died during the terrorist attacks in New York, Washington DC and Shanksville, Pennsylvania on September 11, 2001. Many Americans refer to Patriot Day as 9/11 or September 11. The flag should be flown at half-staff as a mark of respect to those who died on September 11, 2001. Many people observe a moment of silence at 8:46 AM (Eastern Daylight Time). This marks the time that the first plane flew into the World Trade Center in New York.