Pradhosham Rudraasbhishekam for Lord Shiva; Pradosh Vratam is observed on both Trayodashi Tithis i.e. the thithi that occurs twice a month, on the 13th day of the Hindu lunar calendar, during the moon's waxing and waning phases. Shani Pradosham is the Pradosham that falls on a Saturday (Shanivar).

During Shani Pradosham, devotees usually fast and participate in various spiritual practises such as chanting mantras, performing puja (worship), offering performing Rudraasbhishekam , praising lord shiva and singing bhajans.