Tuesday or Mangalvar is dedicated to Lord Hanuman. Upvaas (fasting) on the day is dedicated to Hanuman and Mangal or Mars. Mangalwar, Tuesday, takes its name from the god Mangal or Mars who rules the day and is considered to be a trouble maker, and the fast is to ward off the harmful effects. Red is the preferred color on the day.
Mangalvar Vrat is observed by those couples who wish to have a son. Other benefits include happiness in the family. People who believe in astrology observe fast to alleviate the harmful effects associated with the planet mangal or mars.