a persons birthday on the day of a leap year
Every 200 years
bidecadal
Every 100 years is called a century, made up of 10 decades.
True.
The letter "Y."
An event that occurs once every three years.
it is a a centry
People born on a double leap year
Biennial (biannual is twice a yesr)
El Nino.
Eventual world climate change
Eventual world climate change
When used as an adjective, it means occurring every, or last for, four years. As a noun, it references an event that occurs every four years. (see: http://dictionary.reference.com/browse/quadrennially )
Every 4 years
Biannual can be used in a sentence as an adjective to denote an event that occurs twice a year, or every two years. So, "It's a biannual event" is a rather ambiguous statement.
An example of an occasional climate event that occurs every 3-8 years is the El Niño Southern Oscillation (ENSO). It is a climate pattern that involves the periodic warming of sea surface temperatures in the central and eastern tropical Pacific Ocean, leading to significant impacts on weather patterns worldwide.
The winter Olympics are a sporting event Witch occurs every 4 years. They were first held in 1924 in chamonix,france