Ashtami is the eighth day during a lunar fortnight in traditional Hindu calendar. Shani Ashtami occurs when Ashtami tithi falls on Shanivar – Saturday. Shani Ashtami 2011 dates are July 23, August 6 and November 17.
July 23 Ashtami is the Krishna Paksha Ashtami or the one during the waning phase of moon.
August 6 Ashtami is the Shukla Paksha Ashtami or the one during the waxing phase of moon.
November 17 Ashtami is the Krishna Paksha Ashtami or the one during the waning phase of moon.
Shanivar or Saturday in Hinduism is dedicated to Lord Shani. Ashtami is dedicated to Goddess Durga and also Lord Krishna.
Special pujas and rituals are observed by certain communities in South India on the day. Shani Bhagavan is worshipped on the day. Prayers are held to mitigate his powers in one’s horoscope and assure in peace, health and prosperity.