We generally associate a day for the worship of different gods, like Monday for Lord Shiva, Tuesday for Lord Hanuman. What is the reason that we worship Lord Hanuman on Tuesdays and Saturdays? What is the belief and benefits of worshipping him on the given days of the week?
- Kastabhanjan Hanuman Mandir ( https://en.m.wikipedia.org/wiki/Hanuman_temple,_Salangpur) is an old temple at Salangpur. According to this video: https://youtu.be/lK3nFGMQNnw when Hanumanji saved His devotees from the horrible effects of Sanidev who took the form of a woman to save himself from the anger of Bala-brahmachari Hanumanji. Hanumanji's idol worshipped there shows Sanidev as a female at His feet.An image is enclosed.
So Hanumanji saves His Devotees from Sanidev's rage seems an ancient idea.
- Tulsidasji, a great preacher of Sri Hanuman Worship, describes Him as 'Mangala-Murati' in the Hanuman-Chalisa. This could be the basis of His being worshipped on Tuesdays(Mangala-vara).
According to the Kurma-Puran though, the day for Hanumanji's worship is Arka-vara ie Sunday. (Reference: Hanumat-Kavacham,Purohit-Darpan).
Rahu and Ketu take up Tuesdays and Saturdays respectively
And as I remember (Please correct me if I am wrong) there was an incident of HanumanJi with Rahu, when HanumanJi tried to eat the Sun (I don't have the exact references for this).
So it could be linked to that.
EDIT: I found the correct answer here.
Actually, Hanumanji escaped the lord Shani from the Ravana's prison. Due to this, lord Shani pleased with Hanumanji and gave boon that whoever will worship lord Hanumanji then there will be no effect of lord Shani on him/her