Panchanga (पञ्चाङ्गम्)

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Panchanga (Samskrit: पञ्चाङ्गम्) refers to the Bharatiya calendar system of timekeeping to maintain a record of day to day activities. While Kalamana discusses the different time measurement systems and their role and importance, a Panchanga refers to different times of the day and night and their importance. It is used to identify a particular day with respect to the weekday, month and year of a particular calendar system.

In different societies, depending on their requirements and practices - rituals, social and civil events - various calendar systems have evolved. These systems are essentially based on the solar year either tropical (savana) or sidereal (nakshatra) or lunar years (tithis or luni-solar). In the present times a Gregorian calendar is in use, almost globally, for all administrative and government records and events.

परिचयः ॥ Introduction

Bharatiya Panchanga evolved over thousands of years since the vedic times. Based on the astronomical observations through different phases and periods - Vedanga and Siddhanta - the calendar has undergone continuous refinements. There are essentially two systems followed in Bharatavarsha or Indian sub-continent by different sections of people.

1. Solar (Saura)
2. Luni-Solar (Chandra)

The lunar month is seen as the most natural unit of time with clearly visible pramanas, namely Amavasya and Purnima, in the sky. A lunar month is the period from one new moon (Amavasya) to the next or from one full moon (Purnima) to the next; and it is easily observed without a requirement of any calculations or instruments. A solar month is calculated from the entry into a rashi by the Sun (sankranti) to his entry into the next rashi; and arriving at a sankranti time requires some careful observation of the planetary motions. A Panchanga however, describes many planetary events along with their significance and relevance in astronomical, astrological, ritualistic, social fields, thus to a traditional Sanatana Dharma household the annual Panchanga is indispensable. Their lifestyles are completely entwined with the concept of Kala. The concept of Kala includes both macrocosmic and microcosmic time scales uniquely discussed by Bharatiya shastras, however, of the different such measures of time the daily Panchanga that we use to conduct our activities consists of five aspects.

Most of the festivals in our country are based on the luni-solar (or lunar) calendar. Each of these falls on a particular tithi of a specified Paksha (fortnight) in a particular month or day and a few festivals are based on the nakshatras.

Contents of a Panchanga

A Panchanga typically gives the microcosmic details of five aspects of the day to day time. They are

1. तिथिः ॥ Tithi (Lunar Day)
2. ॥ Vara (Day of the week)
3. ॥ Nakshatra (Asterism)
4. ॥ Yoga
5. ॥ Karana

The coordinates for a day include the tithi present at the time of sunrise, the day of the week, the nakshatra in which the moon is present at the time of sunrise, the yoga and karana at sunrise. Thus the calculations for the day starts with the sunrise. It should be noted that sunrise time changes with the places so the factors become different with change in place.

Apart from the above details, additionally, in a Panchanga one finds the information about the following aspects

तिथिः॥Tithi

Tithi (तिथिः) is a fundamental unit of lunar time (Chandra Mana) - the time taken for the movement of moon by 12 degrees as compared to the Sun. The moon, like the sun, moves from west to east with reference to the fixed stars. The motion of the Moon is much faster than that of the Sun. Moving at a small angle of 5° 8′ towards the ecliptic, the movement of the moon may be considered as moving along the ecliptic itself. Observations show that moon takes an average period of 27.3216615 days to complete a revolution of 360° with reference to the fixed stars, which is called the Sidereal period of the Moon. For the same angular movement of 360° along the ecliptic, in the same direction with reference to the fixed stars, the Sun takes about 365.256364 days, which is the Sidereal period (Year) of the Sun. Thus we have

Motion of the Moon per Day = 360°/ 27.3216615 = 13°10′

Motion of the Sun per Day = 360°/ 365.256364 = 0.98°≈1° 

Tithi = Time taken for the Moon to cover 12° relative to the Sun

Thus tithi is defined as the time taken for the moon to gain about 12°10′ per day over the sun. It is found that the current average interval between two successive Amavasyas is 29.530589 Savana days. This interval between two Amavasyas, where we can see the natural pramana of new moon in the sky is defined as a Chandra Masa or Lunar Month. The lunar month is thus a natural unit for a month, marked by two successive conjunctions of sun and moon (which happens on the new moon day). Approximating the movement of the moon, if it moves by 12° per day, to complete 360° it takes 30 Tithis; this interval is also called as the Synodic period of the moon (synodic means successive conjunctions of the same celestial bodies).

Tithi = [Longitude of the Moon - Longitude of the Sun] / 12° where both longitudes are in degrees

Note: If the longitude of the Moon is less than that of the Sun then add 360° to avoid negative sign and then divide it by 12 to get the tithi.

Chandra Masa (Lunar Month) = 360°/12° = 30 Tithis

This 360° ecliptic is divided into 27 nakshatras, which the moon covers in 27.3216615 days. Thus, we have the moon taking a little more than a Savana or Civil Day (time between two consecutive sunrises) to cover the extent of a nakshatra along the ecliptic.

Determining Amavasya (New Moon) and Purnima (Full Moon)

As the Sun and the Moon are moving in the same direction, the point at which they are in the same celestial longitude as seen from the Earth, when the Moon is said to be "new" or is called Amavasya or New Moon Day when we do not see the moon in the sky. After 24 hours, the Moon will have moved ahead of the sun by 12°10′ time. This separation of the moon from the sun goes on increasing at the rate of 12°10′ per day until it completes a 360° revolution and the moon will again be in conjunction with the sun resulting in Amavasya.

Amavasya occurs when Sun and Moon are on the same celestial longitude (360°)

Purnima or a Full Moon Day happens when the Sun and Moon are on the opposite longitudes 180° apart, when we see the fully bright moon in the sky.

Purnima occurs when Sun and Moon are on the opposite celestial longitudes (180°)

A lunar month can thus be reckoned in two ways both of which are followed in Bharatiya Kalamana, thus we have two calendar systems

• Amanta or Mukhyamana - starting from Amavasya (new moon) to the succeeding Amavasya. This system is followed in Karnataka, Andhra Pradesh, Telangana, Maharashtra and Gujarat.
• Purnimanta or Gaunamana - starting from Purnima (full moon) to the succeeding Purnima. This system is followed in most of the north Indian states of Uttar Pradesh, Bihar, Madhya Pradesh, Rajasthan, Haryana and Kashmir.

चन्द्रकलाः ॥ Phases of Moon

Phases of the Moon is a term used to describe the course of the Moon during the lunar month. During the course of a lunar month, the size and shape of the moon visible from earth appear to change from day to day. Terms such as new, cresent, half, gibbous, and full and then again in the reverse order, until it is new are used to explain the phases of the moon between two Amavasyas. Fifteen tithis or half of a lunar month is called Paksha (पक्षम्) or a fortnight. The Paksha starting from a new moon to the succeeding full moon is called Shukla Paksha (शक्लपक्षम्) or Bright Fortnight and the other Paksha from the full moon to the next new moon is call Krshna Paksha (कृष्णपक्षम्) or the Dark Fortnight. The names of the tithis remain the same in both pakshas, however, this categorization is significant in determination of the coordinates of a day in a given month. Specific activities are associated with each such tithi in a ritual perspective.

तिथयः ॥ Names of Tithis

The tithis or lunar days which make a Chandra Masa have the following names. The fifteenth tithi is called Purnima and the thirtieth tithi is Amavasya.

• Day 1 : Pratipat (प्रतिपत्)
• Day 2 : Dvitiya (द्वितीया)
• Day 3 : Tritiya (तृतीया)
• Day 4 : Chaturthi (चतुर्थी)
• Day 5 : Panchami (पञ्चमी)
• Day 6 : Shasti (षष्टी)
• Day 7 : Saptami (सप्तमी)
• Day 8 : Ashtami(अष्टमी)
• Day 9 : Navami (नवमी)
• Day 10 : Dashami (दशमी)
• Day 11 : Ekadashi (एकादशी)
• Day 12 : Dvadashi (द्वादशी)
• Day 13 : Trayodashi (त्रयोदशी)
• Day 14 : Chaturdashi (चतुर्दशी)
• Day 15 : Paurnami (पौर्णमी)

Names of Lunar Months

It has been previously mentioned that Chandramana is a natural unit of time and so also the naming of lunar months is according to the visible changes in the sky. The name of a lunar month is given based on the nakshatra constellation in which the moon is generally present (or near those nakshatras) on the Purnima day (that lies between two Amavasya days in Amamta system). It must be noted that these names have been used since Vedic times for determining the days when Yajnas have to be conducted.

Thus in the month when moon is present in the asterism of Chitta at the time of Purnima, that month starting from the Amavasya preceding Purnima and ending with the successive Amavasya is called Chaitra Masa according to the Chandra Mana. The names of the 12 Lunar months are as follows

1. Chaitra (चैत्रमासः) : Nakshatra = Chitta
2. Vaishakha (वैशाखमासः) : Nakshatra = Vishakha
3. Jyestha (ज्येष्टमासः) : Nakshatra = Jyestha
4. Aashadha (आषाढमासः) : Nakshatra = Purva Ashada or Uttara Ashadha
5. Shraavana (श्रावणमासः) : Nakshatra = Shravana
6. Bhadrapada (भाद्रपदमासः) : Nakshatra = Purvabhadra, Uttarabhadra
7. Asveyuja (आश्वेयुजमासः) : Nakshatra = Ashvini
8. Kaartika (कार्तिकमासः) : Nakshatra = Krittika
9. Margashira (मार्गशीरमासः) : Nakshatra = Mrgashira
10. Pushya (पुष्यमासः) : Nakshatra = Pushyami
11. Magha (माघमासः) : Nakshatra = Magha/Makha
12. Phalguna (फाल्गुणमासः) : Nakshatra = Purvaphalguni or Uttaraphalguni

Vara - Day of the Week

वार weekdays are seven as in common knowledge globally. They are named after their adhipatis or specific planetary rulers as follows

• Ravi vasara : रविवासरः (Sunday) also called Bhanuvasara
• Soma vasara : सोमवासरः (Monday) also called Induvasara
• Mangala vasara : मङ्गलवासरः (Tuesday) also called Bhaumavasara
• Budha vasara : बुधवासरः (Wednesday) also called Saumya vasara
• Guru vasara : गुरुवासरः (Thursday) also called Brhaspati vasara
• Shukra vasara : शुक्रवासरः (Friday) also called Bhrgu vasara
• Shani vasara : शनिवासरः (Saturday)also called Manda vasara

Surya Siddhanta (11.78) mentions how the days of the week have specific rulers in the given succession. The Sun who is fourth from Saturn is the ruler of the 1st day; the Moon, who is the fourth from the Sun is the ruler of 2nd day; Mars, the fourth from the Moon is the ruler of the 3rd day and so on.