sexagenary

Etymology
From either directly or via, from , from. Cognate with.

Adjective

 * 1) Of or related to the number sixty, particularly:
 * 2) Containing sixty years.
 * The sexagenary cycle is formed by combining the twelve earthly branches representing the years of Jupiter's orbital cycle and the ten heavenly stems of the Shang-era week, stopping halfway through to reflect the pairing of yin and yang terms.
 * : lasting or aged sixty years; sixty-year-old.
 * : base-60.
 * : base-60.

Noun

 * : base-60 numeration.
 * : a sixty-year-old.