An anniversary is a day that commemorates an event that occurred on the same day of the year some time in the past.
Birthdays are the most common type of anniversary where the birth date of a person is commemorated.
Wedding anniversaries are also often celebrated on the same day of the year as the wedding occurred.
Most countries around the world celebrate national anniversaries. These can be the date of independence of the nation or the adoption of a new constitution or form of government.
Many anniversaries have special names; for example 25 years is a Silver Jubilee or silver wedding anniversary; 50 years is a Golden Jubilee; 60 years is a Diamond Jubilee; 70 years is a Platinum Jubilee. Generally speaking the longer the period, the more precious the material associated with it. Anniversaries of nations are usually given by the number of years elapsed in Latin. However, the word is often incorrectly used for different time lengths (eg. a "one month anniversary").
"The Bicentennial Man" is a novella by Isaac Asimov.
The story formed the basis of the novel The Positronic Man (1993), co-written with Robert Silverberg, and the 1999 movie Bicentennial Man, which starred Robin Williams.
The story was originally written for the 1976 American bicentennial -- Asimov was one of several authors commissioned to write a story revolving around the phrase "the bicentennial man", which the writers were to interpret in whatever way they chose.
Bicentennial organizers banked on those events to draw large crowds from throughout the Midwest.
For Kay Fisher of Wilmington, the president of the Clinton County Historical Society, the Ohio Bicentennial was a way to hook her neighbors on local history as well.
The county, she said, had numerous bicentennial events - an Ohio birthday party at Cowan Lake, the bell casting at Wilmington's annual Corn Festival, a play in the local schools about angels in heaven discussing Ohio and its past.