Suidas’ system (the lunar system) is as follows: reckoning a round 30 days per lunar month, 1 saros ... = 222 lunar months ... rather than 3600 years, as in the solar system, the neros ... being one sixth of that ... instead of 600 years, as in the solar system, and the sossos ... one tenth of a neros ... instead of 60 years
Source: wiktionary