What is the Sunday (Ravivāra) vrat for Sūrya, and why is salt avoided?

it begins with arghya to the rising sun and ends with one salt-free meal before sunset; salt is given up as a small, steady tapas.

The Sunday vrat honours Sūrya, the visible deity, and is kept for health, energy and the strength of the Sun in one’s chart. It is usually started on the first Sunday of a śukla pakṣa and kept for 12 Sundays, 30 Sundays or a year.

In the morning, offer arghya from a copper vessel of water with red flowers, rice and a little red sandal while looking towards the rising sun, then recite the Āditya Hṛdayam, Sūrya’s twelve names or the Gāyatrī. Many keep the whole day light and eat once, before sunset, a meal of wheat, jaggery or sweet dishes with no salt and nothing oily. Giving up salt is a gentle restraint that most people can keep without strain.

People with blood-pressure or other conditions should take their medicines and follow their doctor; the arghya and prayer are the heart of the vrat.

Prayer: Āditya Hṛdayam (Rāmāyaṇa, Yuddha Kāṇḍa) · Source: common family practice

Dharma Q&A — vratas, festivals & temples · Ask a Jyotishi your own question