There are two recognized definitions of the term "Flag Day". The first definition is used to designate a day to fly a flag of a certain area, mostly that of nations; the second definition is used to designate a day set aside to honor an event specifically involving a national flag (e.g. creation/adoption).

Father's Day is a secular celebration inaugurated in the early twentieth century to complement Mother's Day in celebrating fatherhood and parenting by males, and to honor and commemorate fathers and forefathers. Father's Day is celebrated on a variety of dates worldwide and typically involves gift-giving to fathers and family-oriented activities.