In the Vedic era, Hindus used the Panchanga (Hindu calendar) to keep track of time, days of the week, and solar & lunar months. The Panchanga was created based off of the sun’s and moon’s movements. A Sanskrit Literature, Surya Siddhanta written in the 4th century, contains detailed astronomical and mathematical calculations about the Panchanga. In this script, jyamiti and trikonamiti are explained in detail. Both of these are derived from Sanskrit, jya– meaning earth and miti– meaning measure and tri- meaning three and konamiti– meaning measures of angles. These mathematical concepts are now called geometry and trigonometry. Many concepts like jyamiti and trikonamiti were invented in India a long time ago and later introduce to Europe in the 15th and 16th centuries. Along with these mathematical concepts, many others were used to form various parts of the Panchanga and are still used to calculate today by only a handful of people to accurately provide information about future eclipses and other planetary movements.
Based off of the moon’s movement around the earth, Paksha and Tithi were created. The moon takes 28-30 days to complete one orbit around the earth. During this orbit, the first 15 days, the moon looks like it is increasing in size and looks brighter. The next 15 days, the moon looks like it is decreasing in size and at the end of these 15 days, we cannot see the moon. These 15-day changes in the moon’s movement are called Paksha. This is a Sanskrit word meaning sides. The way we see the moon from earth is how the Paksha is named. The first 15 days are called Shukla paksha and the next 15 days are called Krishna paksha. To summarize, Shukla (bright) and Krishna (dark) paksha describe the waxing and waning moon. Shukla paksha and Krishna paksha together form a maasa (lunar month). Each individual day in a maasa is called Tithi and each paksha has 15 tithis (days). Tithi is the time taken for the longitudinal angle between the Moon & the Sun to increase by 12 degrees. The names of tithis (derived from Sanskrit numbers) are as below:
Shuklapaksha: pratipada, Dvitiya, Tritiya, Chaturthi, Panchami, Shashti, Saptami, Ashtami, Navami, Dashami, Ekadashi, Dwadashi, Thrayodashi, Chaturdashi, Pournami.
Krishnapaksha: Pratipada, Dvitiya, Tritiya, Chaturthi, Panchami, Shashti, Saptami, Ashtami, Navami, Dashami, Ekadashi, Dwadashi, Thrayodashi, Chaturdashi, Amavasya.
People in India use two different lunar months. The month which ends on Amavasya (dark moon day) is called Amanta. The month which ends on Pournami (full moon day) is called Poornimanta. Amanta maasa is more widely used. The 12 maasas form one Chandramana Varsha (a year based on the moon’s position). The names of these maasas are as below:
Chaitra, Vaisakha, Jyeshta, Aashaadha, Shraavana, Bhadrapada, Aswayuja, Kartika, Margashirsha, Pushya/Poush, Maagha, Phalguna.
In Jyotisha, planetary movements are calculated with respect to Earth’s position. When the earth orbits the sun, it appears as if the sun is moving around the earth. This movement, however, is not real. When using the earth as a reference point for the sun’s “movement”, there is an imaginary area around the earth which extends approximately 9 degrees on each side of the imaginary elliptical path of the sun. This area is known as Rashi Chakra (Zodiac Belt) or Bhachakra. The rashi chakra has a total of 360 degrees and this belt is divided into twelve 30-degree sections, each section is known as a rashi. The sun takes 30-days to cross one rashi and 1 year to cross all 12 rashis. Each rashi contains clusters of Nakshatras(constellations) that form various shapes. During the Vedic era, Maharishis named these rashis based on the shape of these Nakshatra clusters. The names of these rashis also known as Souramaana Maasa (Solar months) are as below:
Mesha, Vrushabha, Mithuna, Karka, Simha, Kanya, Tula, Vruschika, Dhanu, Makara, Kumbha, and Meena.
There are a total of 27 Nakshatras in the Rashi Chakra. Each Nakshatra has 13 degrees and 20 minutes. In each nakshatra, there are 4 paadas(quarter) and each paada contains 3 degree 20 minutes. In total there are 108 paadas in the Rashi Chakra. The order of the Nakshatras start in Mesha Rashi and end in Meena Rashi. The Nakshatras are as below:
Ashwini, Bharani, Krittika, Rohini, Mrigashira, Aardra, Punarvasu, Pushya, Aashlesha, Makha, Purva Phalguna, Uttara Phalguna, Hastha, Chitra, Swathi, Vishakha, Anuradha, Jyeshtha, Moola, Purvashaadha, Uttarashaadha, Shravana, Dhanishtha, Shatabhisha, Purva Bhadrapada, Uttara Bhadrapada, Revathi.
In the next post, we’ll learn more about seasons!
Jataka Phala Saara 