Historical Perspective of Samvatsari Day and Jain Calendar

Author(s): Pravin K Shah
Publisher: JAINA Education Committee

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The Jewish (Hebrew), Hindu lunar, Buddhist, and Tibetan calendars are all lunisolar, and
so were the Japanese calendars until 1873 and the Chinese calendars until 1912. • The Islamic calendar is a pure Lunar Calendar because its date (Tithi) indicates the moon
phase but its months are not in phase with the time of the solar year or the season. It does not adjust its calendar to coincide with the SUN or the season. Hence no extra month is added every three years. The Gregorian calendar (English CE) is a pure Solar Calendar and its date indicates the
time of the solar season but not the moon phase. Tithi (Day or Date) In a Lunisolar calendar the day or date is recognized as Tithi. The angular distance (measured anticlockwise) between the Sun and Moon as measured from the Earth location can vary between 0° and 360°. The 360 degree rotation indicates the Moon has completed one circle around the Earth, which is the completion of one Lunisolar month. Normally there are 30 days in a month hence 360 degree is divided into 30 parts. Each part ends at 12°, 24° and so on. The circle ends at 360° which a month. The time spent by the Moon in each of these parts (i.e. the time taken by the Moon to travel the angular distance of 12°) is called one Tithi. This is a very simple explanation. In reality the calculation is quite complex because the Earth and the Sun have moved their position during this time and the value changes to close to 13 degree. Each Lunisolar month has two Paksha-s or fortnights (15 Tithis or days in a fortnight). The first 15 Tithi-s constitute the bright fortnight or Shukla or Sud Paksha and the next 15 Tithi-s constitute the dark fortnight or Krishna or Vad Paksha. The Tithi-s are indicated by their Paksha and ordinal number within the Paksha. The days are not labeled separately from number one to thirty as in the solar calendar, but the Tithi is their only label and each Tithi has a unique name. The 15th Tithi of the bright fortnight or Sud (Full Moon Day) is called Purnima and the 15th Tithi of the dark fortnight or Vad (Dark Moon or New Moon Day) is called Amavasyä. The duration of a day (between the two consecutive Sunrises) is approximately 24 hours. However the duration of each Tithi varies between 22 hours and 26 hours because the Moon rotates around the Earth in a slightly tilted position and hence the angular velocity is not constant with respect to the particular location of the Earth (This is also a very complex calculation). Structure of Jain Calendar as per Agam Literature The Jain Ägam literature (ref - Chandra Prajnapti and Surya Prajnapti) defines a five year cycle of a Jain calendar. This is known as one Yuga. In the Jain Agamic calendar (1) One "Tithi" is eliminated after every 61 days (2) An additional month is added after every 30 months. (3) During a five year cycle, the month of Posha (the 3 month of the current Jain calendar) is
added after 30 months and the month of Ashädh (the 9 month) is added after 60 months. This description indicates that none of the current Jain calendars published by various Jain sects are based on Jain Agam literature. Also there is a strong indication in the Agamic Jain calendar, the Jain year ended on Ashadha Sud 15 and the New Year begins on Shravan Vad 1 as per Rajasthani calendar naming convention or Ashadha Vad 1 as per Gujarati calendar naming convention (see the following note).