== MEASURING TIME ==

Annual - every year

Biannual - two times a year

Bicentennial - every 200 years

Biennial - every two years

Bimonthly - every two months

Centennial - every 100 years

Decade - 10 years

Decennial - every 10 years

Duodecennial - every 12 years

Lustrum - for five years

Millennium - 1,000 years

Novennial - every 9 years

Octennial - every 8 years

Perennial - year after year

Quadrennial - every 4 years

Quadricentennial - every 400 years

Quincentennial - every 500 years

Quindecennial - every 15 years

Quinquennial - every 5 years

Score - 20 years

Semiannual - every 6 months

Semicentennial - every 50 years

Semidiurnal - twice a day

Septennial - every 7 years

Sesquicentennial - every 150 years

Sexennial - every 6 years

Tricennial - every 30 years

Triennial - every 3 years

Undecennial - every 11 years

Vicennial - every 20 years