When did solon reform Athens laws and society?

In 494 BCE he was appointed to avert an impending civil war between the large landowners and the small farmers. He didn't reform law and society - made some very modest changes, trying to please both sides, abolishing debt slavery and introducing an assembly of the propertied classes. It had limited success, and 30 years later the majority appointed a tyrant to limit the power of the rich and govern for the majority. The tyrants came into disfavour, and 80 years after Solon, Cleisthenes established a limited democracy, following Sparta's successful example.