sexagesimal adj.

"composed of or produced by sixties; pertaining to division into sixty," 1680s, from Medieval Latin sexagesimalis, from Latin sexagesimus "the sixtieth," from sexaginta "sixty." Sexagisema, "second Sunday before Lent" (eighth before Easter), is from late 14c. (Sexagesime), from Medieval Latin sexagesima (dies) "the sixtieth (day)."