Each of the seven days in a week has a special significance and is apportioned to one or more Hindu gods or goddesses and there are several folklores associated with the ritual fasting observed on these days.
Fasting Associated with the Daily Deities Hindu devotees keep occasional 'upvaas'or fast corresponding to the fulfillment of a vow or a belief and 'vratas' (fasting and observance of religious rituals) that is analogous with material or other gains. Apart from these special occasions, many devotees also fast on a particular day of the week dedicated to a particular god in the Hindu pantheon to appease him/her. Ancient sages used observances like ritual fasts to spread the awareness of different gods. Fasting and other rituals pave the path of the divine for the devotees to realize god, which is considered the sole purpose of human existence.
The Navagraha - the 9 Celestial Bodies
Navagraha represents the nine celestial influencers in Vedic Astrology. The seven days are named after the seven celestial bodies of our solar system - the Sun, Moon and the planets. Apart from these, mention should be made here of Rahu and Ketu, the two nodes of the Moon - the north and the south, the points of intersection of the paths of the Moon and the Sun. Lunar eclipses occur when the Moon and the Sun are at Rahu or Ketu. So, Navagraha comprises of:
1. Surya (Sun)
2. Chandra (Moon)
3. Mangala (Mars)
4. Budha (Murcury)
5. Brihaspati (Jupiter)
6. Shukra (Venus)
7. Shani (Saturn)
8. Rahu - Dharma – Service to others
9. Ketu - Karma
Sunday (Ravivar) Surya (Sun God): The planetary deity presiding over Ravivar (Sunday) God: Sunday is dedicated to Lord Surya or Suryanarayana - the Sun God. Ritual: After a ritual bath and cleansing of their body and their house and surrounding, devotees offer red color flowers to Surya and apply red sandalwood paste as 'tilak' on their forehead. They keep a fast throughout the day and eat food only once before sunset and avoid salt, oil and fried food items. Alms are also given on that day. Ravivar Vrat or Sunday fasts help in fulfilling ones wishes and it is believed that all kinds of skin diseases get cured. Color & Gem: Red and pink are the color of the day and ruby the preferred gem. Celestial Body: Sun or Surya rules Sunday