Notes: All timings are represented in 12-hour notation in local time of Cambridge, United States with DST adjustment (if applicable).
Hours which are past midnight are suffixed with next day date. In Panchang day starts and ends with sunrise.
Chaturdashi Tithi during Krishna Paksha is observed as Masik Shivaratri or Masa Shivaratri and staunch devotees of Lord Shiva observe fast and worship Shiva Linga on all Shivaratris in the year. In a year there are usually twelve Shivaratri days.
Shivaratri which falls during Shravana month is known as Sawan Shivaratri. As whole Shravana month is dedicated to perform Shiva Puja, Masa Shivaratri during Sawan month is considered highly auspicious. However, the most significant Shivaratri which is known as Maha Shivaratri falls during February or March which corresponds to Phalguna month according to North Indian calendar.
Famous Shiva temples in North India, Kashi Vishwanath and Badrinath Dham arrange special Pujas and Shiva Darshan during Sawan month. Thousands of Shiva devotees visit Shiva shrines during Sawan month and perform Gangajal Abhishekam.
Sawan Shivaratri is more popular in North Indian states - Uttarakhand, Rajasthan, Uttar Pradesh, Madhya Pradesh, Punjab, Himachal Pradesh and Bihar where Purnimant Lunar Calendar is followed. In Andhra Pradesh, Goa, Maharashtra, Karnataka, Gujarat and Tamil Nadu where Amavasyant Lunar Calendar is followed Sawan Shivaratri corresponds to Ashadha Shivaratri.
One day before Shivaratri Vratam, most likely on Trayodashi, devotees should eat only one time. On Shivaratri day, after finishing morning rituals devotees should take Sankalp (संकल्प) to observe full day fast on Shivaratri and to take food on next day. During Sankalp devotees pledge for self-determination throughout the fasting period and seek blessing of Lord Shiva to finish the fast without any interference.
On Shivaratri day devotees should take second bath in the evening before doing Shiva Puja or visiting temple. Shiva Puja should be done during night and devotees should break the fast next day after taking bath. Devotees should break the fast between sunrise and before the end of Chaturdashi Tithi to get maximum benefit of the Vrat. According to one contradictory opinion devotees should break the fast only when Chaturdashi Tithi gets over. But it is believed that both Shiva Puja and Parana (पारण) i.e. breaking the fast should be done within Chaturdashi Tithi.
Sawan Shivaratri is also spelled as Shravana Shivratri. Hariyali Amavasya, another auspicious day during Sawan month, falls one or two days after Sawan Shivaratri day.