Memorial Day, which is observed on the last Monday of May, commemorates the men and women who died while in the military service. In observance of Memorial Day, fly the United States flag at half staff from sunrise until NOON , and then raise it to full height from noon to sundown.
United States Flag Code
Section 7.M
The flag, when flown at half-staff, should be first hoisted to the peak for an instant and then slowly lowered to the half-staff position. The flag should be again raised to the peak before it is lowered for the day. On Memorial Day the flag should be displayed at half-staff until noon only, then raised to the top of the staff.
Click here to see the entire US Flag Code….