BIANNUAL or BIENNIAL?

English for Today by Ganiu Abisoye Bamgbose (Dr GAB)

BIANNUAL or BIENNIAL?

I come to LASU twice every year for my association’s ~biennial~ conference (nonstandard).
I come to LASU twice every year for my association’s *biannual* conference (standard).
A biannual event happens twice a year.

Since the programme comes up once every two years, then it’s a ~biannual~ programme (nonstandard).
Since the programme comes up once every two years, then it’s a *biennial* programme (standard).
A biennial event happens or is done once every two years.
GAB