Sade Sati is the period when Saturn transits the sign before your Moon sign, your Moon sign itself, and the sign after it. Each phase lasts about two and a half years.
Is it always bad?
No. Saturn rewards discipline and patience. Many people make lasting progress in their careers during Sade Sati. The effects depend on Saturn's strength in your birth chart and your running dasha.
Common remedies
Regular Shani mantra recitation, service to elders and workers, and honesty in dealings are the classical recommendations. Gemstones should only be worn after a proper chart check.
Ready to see it for your own chart?See Sade Sati in your Kundli