Flag Day is celebrated on June 14, the anniversary of the 1777 adoption of the first “American” flag by the Continental Congress. In 1916, President Woodrow Wilson issued a proclamation that officially established June 14 as Flag Day; on August 3, 1949, National Flag Day was established by an Act of Congress, although Flag Day is not an official federal holiday.
There are plenty of patents with patriotic themes, including flag displays, but only a handful expressly mention “flag day.” One of these is U.S. Patent No. 4,872,794 on a Flagstaff with Protective Housing, which provides a protective cover for a flag when it is not on display:
Happy Flag Day. Go celebrate its 245th birthday.