Question: how many years is quarter of a century
Answer: in - derived term Other terms Comments 1⁄2 yearly Semiannual 1 year Annual Paper 2 years Biennial Cotton 3 years Triennial Leather 4 years Quadrennial Linen 5 years Quinquennial Wood 6 years Sexennial Iron 7 years Septennial Wool 8 years Octennial Bronze 9 years Novennial Copper 10 years Decennial Tin / Aluminium 11 years Undecennial Steel 12 years Duodecennial Silk 13 years Tredecennial Lace 14 years Quattuordecennial Ivory 15 years Quindecennial Crystal 20 years Vigintennial / Vicennial China / Porcelain 25 years Quadranscentennial Silver jubilee 40 years Quadragennial Ruby jubilee 50 years Semicentennial / Quinquagenary Golden jubilee 60 years Sexagennial / Sexagenary Diamond jubilee 65 years Sapphire jubilee 70 years Septuagennial Platinum jubilee 100 years Centennial Centenary 125 years Quasquicentennial Term is broken down as quasqui - ( and a quarter ) centennial ( 100 years ) .