According to the Hindu calendar, the Pradosh Vrat is observed on the Trayodashi Tithi falling during the Pradosh time. This fast is primarily dedicated to the worship of Lord Shiva. This time, the Trayodashi of the Shukla Paksha of the month of Vaishakha falls on May 20th. On this day, the Pradosh Vrat will be observed. It is customary to worship Lord Shiva along with Goddess Parvati on this date.
