Pradosh Vrat is observed on the 13th day of a fortnight and there are two Pradosham in a Hindu month. Lord Shiva and Goddess Parvati are worshipped in the evening during twilight on this day. (on the Trayodashi of both lunar fortnights (Shukla and Krishna Paksha).)
The Navagraha Chalisa is a powerful prayer which eliminates the adverse effects of all the nine graha (planets) Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn, Rahu and Ketu. The recitation of this prayer is beneficial in bringing harmony into your life and keeping the balance intact. ( Navagraha Chalisa नवग्रह चालीसा)
Navghraha Chalisa : श्री नवग्रह चालीसा
Somvar or Monday Vrat is one of the prominently known fasting practices observed in the Hinduism. Somar vrat is dedicated to worshipping and propitiating Lord Shiva and Mother Parvati. All Mondays are devoted to the worship of Shiva as this day is sacred to Lord Shiva.