Traditionally in Sanatana Dharma, some days of the week are dedicated to the worship of a certain Manifestation/ aspect of the Divine.

In that day the devotees are preforming a special puja, reading the scriptures related to this devata and some are fasting.

The Hindu week and the special worship days:

The days bellow are of the fortnight of the Hindu Month: (see the Hindu Calender section)

Caturti- (the 4th of each part of the Hindu month)Lord Ganesh

Astami (the 8th of each part of the Hindu month)- Devi

Ekadasi- (the 11th of each part)Lord Vishnu/Krishna/Rama

Pradosh- (the 13th of each part)- Siva Ratri (in fact Siva Ratri comes every month but a big celebration is done once a year).