• Ordinarily [the flag of the United States] should be displayed only between sunrise and sunset, although the Flag Code permits night time display “when a patriotic effect is desired.” Similarly, the flag should be displayed only when the weather is fair, except when an all-weather flag is displayed.
  • It should be illuminated if displayed at night.


Out of practical necessity, five of the six U.S. flags standing on the moon (the Apollo 11 flag was blown over during departure) fly continuously, even during the two-week lunar night.

“United States Flag Code”