Tuesday, which is known as Mangalwar or Chowai or Chovazhcha, is considered inauspicious by some Hindu communities, especially in South India (Kerala). No journey is commenced on Tuesday as it is bad. Auspicious ceremonies are also avoided on the day. Some scholars indicate that that it is suggested in the Brihat Samhita of Varahamihira that Tuesday should be avoided for auspicious functions.
Mangalwar or Tuesday is ruled by Mars or Mangal. Mars is also known by the name of Angarak, Kujan, Agneya and this all indicates that the planet is red and is associated with heat. He is also believed to kick start fights and is also considered to be responsible for cuts and bruises on the body. He is also believed to create unwanted competitions among people.
Tuesday begins at the highest influence point of Mars and therefore he is believed to have control throughout the day.
These are some of the reasons why Tuesday is held inauspicious.
But it must also be remembered that Tuesday is considered the most auspicious day to worship Lord Hanuman – Sankat Mochan. Tuesday is also highly auspicious to worship Lord Ganesha.