A triennial event happens every three years.
you multlpy 12 by 65 for every year there is 12 months and you get 780
Something that happens every six years is sexennial.
Something that happens every three years is a triennialevent.
Something that happens once a century.
As far as I know, nothing special happens every 100,000 years. A full precession cycle takes about 26,000 years.
Quinquennial = something that happens every 5 years. Lustral = also something that happens every 5 years or we could invent: semi-Decennial: where semi is half and Deccennial happens every 10 years.
It happens every 200 years.
The Olympics.
Something that happens every 5 years
the Olympics
the world cup ( I think) happens every 3 years or 4 years?