Sade Sati

Sade Sati is Saturn's ~7.5-year transit through the sign before your natal Moon, your Moon's sign itself, and the sign after — three ~2.5-year phases. Classical Vedic considers it a time of accountability and slow, hard-earned growth.

The three phases

Each cycle has three ~2.5-year phases: Starting (Saturn enters the 12th house from Moon), Peak (Saturn enters Moon's sign), Ending (Saturn enters the 2nd house from Moon).

Source: Saturn transit rules from BPHS Ch. LIII; phase divisions from Phaladeepika