Something that happens once a century.
Something that happens every six years is sexennial.
Some things that happen once every four years include: - Leap Years - US Elections - The Olympics
A millennium happens once every thousand years.
THAT YOUR AGE ON THIS DAY IS2022
Something that occurs once every 100 years is known as centennial.
Biennial or biannual can refer to something which happens every two years.
A leap year happens only once every four years; that is also true of US Presidential elections.
The Olympics is an event that happens once every 4 years, bringing together athletes from around the world to compete in various sports.
You have the world cup, the U.S president is elected, the Olympics are held , and so is the Euro cup. This all happens every four years.
the word is novennial....
It is called Leap Year, and the day that is added is February 29th. We only get that day once every four years.