The Indian standard of time has two standards: Vikram Samvat (57 BC) and Shak Samvat (78 AD). The Shak Samvat is the official calendar of India. It started after Vikram Samvat and is about 78 years behind the English calendar. In fact, it got the status of the ‘Indian National Calendar’ on 22nd March 1957, or 1st Chaitra 1879.
The government of India decided to adopt the Shak Samvata as the Indian national calendar to have a uniform calendar because the country was using about 30 different calendars at that time. The goal was to create a calendar that avoided the Adhik Masa, which is added to lunar calendars. Due to a mathematical mistake, the dates of key solar occurrences in the lunar calendars are also shifted forward or backwards. To avoid this, an extra month is added to the lunar calendar every three years.
The Shak Samvat calendar is structured similarly to the Gregorian Calendar, with 365 days and 12 months. Chaitra, the first month of the Saka Samvat, begins on March 22, which coincides with March 21 during the leap year. The twelve months (in order) in this calendar are Chaitra, Vaishakha, Jyeshtha, Ashadha, Shravana, Bhadra, Ashwin, Kartika, Agrahayana, Pasha, Magha, and Phalguna.
The Shak Era is thought to have been established by King Shalivanhana of the Shatavahana dynasty. Gautami was King Shalivahana’s mother, according to the Matsya Purana. Adiseshan blessed the birth of King Shalivahana. King Shalivahana had a difficult upbringing, but he got numerous benefits as a result of harsh penance from God, as a consequence of which King Shalivahana acquired mastery in the fields of courting and battle. It was established to commemorate the military achievements of king Shalivanhana.
The Kannada poem Udbhatakavya by Somraj in 1222 CE is evidence of the connection between the Shalivahanas and the Shak era. Out of these poems, the Muhurta-Martand tells that the Saka era began with the birth of Shalivahana. King Shalivahana’s victory over King Vikramaditya is written in Kalpa Pradip in 1300 AD.
The Shak Samvat is very important to Indian history. It was used in the golden era of the Mauryan and Gupta ages. It was employed in practically all astrological computations and books in the early period. Scholars distinguish between two Shak period systems: the Old Shak era and the Shak era of 78 CE, or simply the Shak era. This method appears often in epigraphic data from southern India. The Vikrama era, which is employed by the Vikramaditya calendar, is a parallel North Indian system.
The Shak calendar, like the Gregorian calendar, is based on a lunisolar computation of time and contains 12 months and 30-31 days per month. The months of this calendar are based on tropical Zodiac signs rather than the sidereal signs used in the Hindu calendar. It is both solar and lunar by nature with lunar months and a solar year. The zero year is marked by the 78th vernal equinox.
It is adopted by Hindus in South East Asian nations such as Java, Bali, and Indonesia. On March 22, or Shak New Year, Bali observed Nyepi, also known as the Day of Silence. Nepal Samvat, the country’s recognised calendar, is obviously a development of the Saka Calendar.