A **flag day** is a date set by law or custom on which the national flag is flown in honour of a national event, person or institution. Flag days are observed by hoisting the flag at full-staff from sunrise to sunset, in addition to its ordinary display. National lists of flag days vary widely: some are tied to historic events, others to royal birthdays or constitutional anniversaries.
**Example**: 14 June is observed as Flag Day in the United States, commemorating the adoption of the Stars and Stripes by Congress in 1777.
**See also**: [sunrise-to-sunset-rule](/glossary/sunrise-to-sunset-rule/), [full-staff](/glossary/full-staff/), [hoisting](/glossary/hoisting/), [vexillology](/glossary/vexillology/)