20 July 2013 is Shani Pradosha Vrata, Pradosham Shiva Pooja. As it falls on Saturday (Shanivara), it is also referred to as Shani Pradosha Vrata.
It falls on Trayodashi in Shukla Paksha in Ashada Month in Hindu calendars followed in North Indian states and in Maharashtra, Karnataka, Gujarat, Goa and Andhra Pradesh calendars.
It falls in Aadi Masam in Tamil calendar, Karkidaka Masam in Malayalam Panchangam and Shraban Month in Bengali Panjika.
Shani Graha Shanti / Shani Dosha Nivarana Homam are performed by some devotees on Shani Pradosh Vrat.
Pradosh Puja time is 4.30 to 6’0 clock in the evening. Pradosha Astakam is an auspicious prayer chanted during Pradosh Shiv Pujan.