You could refer to it as a quarterly event.
It is a triennial event. A triennial event happens three times a year.
lyphsucktion
An event that occurs five times a year is often referred to as a "quintannual" event. An example could be a seasonal festival or a quarterly meeting that takes place in five distinct sessions throughout the year. Such events can vary widely in nature, from community celebrations to corporate gatherings.
An event of some sort that happens twice a year.
An annual event starts with A and happens once a year.
2 times a year
Something that happens once a year.
Biennial is a word describing an event that happens every two years.
There are 365 days in a non-leap year, so an event would occur 365 times in one year. However, if it's a recurring event that happens on a specific day of the week or month, it would occur fewer times depending on the pattern.
equinax
An annual event
yes i'm positive it happens every year