For any auspicious function to be conducted it is a tradition to consult the panchaangam to fix the time for starting the function so that the function goes on smoothly. So, the panchaangam has been a part and parcel of sanaatanadharma. panchaangam is one of the applications of jyotisha shaastra and in use even present times.

In this section we shall impart the knowledge of the basics of panchaangam and the science behind the development of panchaangashaastra. It may be noted that the strong knowledge of astronomy, the knowledge of the movement of the celestial objects of sun, moon, and the planets, was developed by our rushis long before the discovery of modern-day astronomy. The names of the weekdays, months and the years are all on a scientific basis in an Indian traditional calendar. The same have been modified by the modern-day names. The great sage varaahamihira was the father of astrology and astronomy, so he has postulated the theory with such accuracy that even today we follow the same principles and find the movement of the celestial objects as per the same predictions. Thus, knowledge of panchaangam is an essential part of sanaatanadharma.

panchaangam and its importance.

panchaangam means five angaas or parts.

      तिथिवारञ्चनक्षत्रं योगःकरणमेव च ।

      पञ्चाङ्गमिति विख्यातं कालोऽयं कर्मसाधकम् ।।

tithivaaranchanakshatram yogahkaranameva ca |

panchaangamiti vikhyaatam kaaloyam karmasaadhakam ||

Before discussing panchaangam, we must know about astrology and solar system.  The various theories have been set up to discover the influence of the planets upon the terrestrial phenomena.  Astrology is the most ancient of all sciences and had reached considerable perfection in bhaarat thousands of years ago.  Astrology is the science which comprises the foretelling of the regular movements of the planets and stars, the fortunes and misfortunes of human beings, fates of nation, earthquakes, volcanic eruptions, cyclones, and other incidents relating to terrestrial phenomena.  In samskrit it is called hora shaastra means the science that treats time.  It is also called jyotisha or the knowledge of light from jyoti or light which is the root cause for all known creation.  According to the western interpretations, Astrology is derived from aster – a star and logos – reason or logic.

यथा शिखा मयूराणां नागानां मणयो यथा ।

तद्वद्वेदाङ्ग शास्त्राणां ज्योतिषं मूर्धनि स्थितम्।।

Yathaa shikhaaa mayooraanaam naagaanaam manayo yathaa |

tadvadvedaanga shaastraanaam jyotisham moordhani sthitam ||

jyotishya is the important anga of vedapurusha out of shadaangas/ vedaangas.  sarvedriyaanaam nayanam  pradhaanam like jyotishya is netra sthaana   of vedapurusha.

स्कन्द त्रयात्मकं शास्त्रम् ।

Astrology is skanda trayaatmaakam means, it has three bhaagas viz- siddhaanta, ganita, and samhitaa or phalitaa bhaagam. panchaangam belongs to siddhaanta bhaagam.  The various elements encompassing all matter are altered by the motions of the eternal power.  The acts of creation (srushti), protection (sthiti) and destruction (laya) are embedded in the womb of the all-powerful TIME/kaala, and these variations are brought about as consequences of subtle power.  The sun, by his daily movements and the change of seasons, brings to perfection the embryo in plants and animals and brings about various changes on the earth.  The moon being nearest to the earth exercises much influence on it and rivers swell, the tides of the sea increase in size, and the plants and animals get affected.

The sun as the central figure which predominates over the entire arrangement of the celestial system and the other plants and stars are directed by his rays.  The zodiac is a broad band or belt in the heavens extending 9 degrees on each side of the ecliptic. The ecliptic or the path of the sun passes exactly through the center of the zodiac longitudinally. It is an imaginary circle of 360 degrees and divided this zodiac into 12 equal parts of 30 degrees each, each being named after a constellation.  The quality of each sign/raashi is not equally spread, but every degree in a sign/raashi has its own peculiar qualities.  The zodiac/ raashichakra known as bhachakra in samskru/sanskrit revolves on its axis once in a day from east to west.     

The planetary orbs, which the ancients recognized as having most powerful influences on our earth are seven, leaving aside the shadowy planets raahu and ketu.

As inhabitants of the earth, we are concerned with the influences of these celestial bodies on our planet.  All the planets perform the double function of not only revolving on their own axis, once in a day (from west to east) but also round the sun. According to soorya siddhaanta, saturn/shani is the most distant planet from the earth. jupiter/guru, mars/angaaraka, the sun/soorya, venus/shukra, mercury/budha, and moon/chandra come next in the order of their distance from the terrestrial globe.  Thus, we see that the nearest planet to our own orb is moon/chandra.  The velocity of each planet diminishes as its distance from the earth increases.

The sun moves at the rate of roughly 1 degree of this circle of light (zodiac/raashi chakra) in one day composed of 24 hours and it takes 365 days and 6 hours to complete a circuit round the zodiac. The moon takes the average rate 4 ½ ghati or 1 hour 48 minutes to traverse through a degree of this space. Mars moves at the average rate of 45 days for 30 degrees or takes 1 ½ day per degree.  Mercury moves at the average rate of 1 ½ degrees a day but on account his closeness to the sun and due to the solar influence, he is very unsteady.  Mercury completes his average run in 27 days. He gets into forward(atichaara) and backward motions(vakra) from the sun and attains what is called combustion.  He hardly takes a day to move in each degree, but moves on more rapidly for some time, gets in front of the sun and then begins to move slowly and goes backwards from the sun. These two states of combustion moving forward and backward from the position of the sun are designated in the astronomical works as praagastambha, paschandastambha. praaga indicates towards east of the sun and paschand indicates towards west of the sun.  In these double motions of backward and forward mercury never gets away more than 28 degrees in either direction from the sun.  Jupiter moves at average rate of 1 year in each rashi of 30 degrees, sometimes it will be a little less than a year in 12 signs. 

Venus moves at the rate of 1 degree per day.  Saturn is the slowest moving planet of the lot.  He takes about 2 ½ years or 30 months to move in a sign of 30 degrees and thus he takes 1 month to move in a degree.  raahu and ketu which revolve in the apasavya order i.e. from east to west, takes 18 months to travel through each sign of the zodiac.  All the Planets except the sun, the moon, and the shadowy planets raahu and ketu undergo retrogression or vakra.   

               This is brief knowledge about solar system.

               Now coming to the present topic of panchaangam, panchaanga means five angas or parts: They are: 

1. tithi 2. vaara
2. nakshatra 4. yoga &
3. karana

Before that we must know time measurement or kaala swaroopa. 

1. yuga 2.  samvatsara
2. ayana                                                    4.  rutu
3. maasa 6.  paksha
4. ahoraatra                                               8.  yama
5. muhoorta                               10. vigati
6. praaNa                                                  12. truti etc.

Mainly time / kaala are 6 types:

(1) samvatsara (year)                         (2) aayana (6 months) 

(3) rutu (2 months)                              (4) maasa (1 month)

(5) paksha (1/2 month) and               (6) dina (1 day)

This is kaalachakra.

samvatsara: In sanaatanadharma 60 lunar years constitute one cycle. They are: 

1. prabhava 2.  vibhava
2. shukla 4.  pramodoota
3. prajotpatti                                        6.  angeerasa
4. shreemukha 8.  bhaava
5. yuva 10. dhaatu
6. eewshwara   12. bahudhaanya
7. pramaadi 14. vikrama
8. vrusha 16. chitrabhaanu
9. swabhaanu 18. taaraNa
10. paarthiva 20. vyaya
11. sarvajit 22. sarvadhaari
12. virodhi 24. vikruti
13. khara 26. nandana
14. vijaya 28. jaya
15. manmatha    30. durmukhi
16. hevilambi     32. vilambi
17. vikaari 34. shaarvari
18. plava 36. subhakrutu
19. shobhakRutu 38. krodhi
20. vishwavasu 40. paraabhava
21. plavanga 42. keelaka
22. soumya 44. saadhaarana
23. virodhikrutu 46. pareedhaavi
24. pramaadeecha 48. aananda
25. raakshasa     50. nala
26. pingala 52. kaalayukti
27. siddhaarthi                   54. roudri
28. durmati 56. dundhubhi
29. rudhirodgaari 58. raktaakshi
30. krodhana    60. akshaya

The first year of the cycle prabhava denotes the evolution of a new creative force which apparently is supposed to end in the last or 60^th year after getting fully matured. When the New Year gives rise to a new force, a new name of year is given. Prabhava (1^st year) is the starting of the year cycle. In vibhava, (2^nd year) this force is expanded. shukla (3^rd year) denotes its vitality, pramodoota (4^th year) causes development, prajotpatti (5^th year) increases activities. angeerasa (6^th year) connotes the different forms the newly evolved force takes and similarly the names are given for all the 60 years indicative of the functions that the force is supposed to do till the year akshaya or no destruction (60^th year) sets in which that the force generated in prabhava (1^st year) has been destroyed.

ayanaa: There are two ayanas or periods in a year. 

(1) uttaraayana – Commences from the winter solstice, when the sun enters capricorn or makara raashi and moves in a northern direction and 

(2) dakshinaayana begins with the summer solstice or the sun enters caner or karkaataka raashi and moves in southern direction.

rutus or seasons: The principal seasons in sanaatanadharma are six whereas the western countries consider only 4 seasons.  The six seasons / rutus are:

1. vasanta rutu – chaitra & vaisaakha maasas (Spring season)
2. greeshma rutu – jyeshta & aashaadha maasas (Summer)
3. varsha rutu – shraavana & bhaadrapada maasas (Rainy season)
4. sharad rutu – aashwayuja & kaarteeka maasas (Autumn)
5. hemanta rutu – maargasheersha & pushya maasas (Winter) & 
6. shishira rutu – maagha & phaalguna maasas (Winter)

maasa (Month): 12 Lunar months consist of one year. They are:

1. chaitra (March-April) 2. vaishaakha (April-May)
2. jyeshta (May-June) 4. aashaadha (June-July)
3. shravana (July-August) 6. bhaadrapada (August-September)
4. aashwayuja (Sep-Oct) 8. kaartika (October-November)
5. maargashira (Nov-Dec) 10. pushya (December-January)
6. maagha (January-February) 12.phaalguna (February-March)

The name of each Lunar month is given because of the constellation/nakshatra falling on the full moon day of the month. Ex: chitta star falls on chaitra poornima. 

Similarly, there are 12 solar months in a year for those who follows solar year. Solar month means the sun transits from one sign to another sign after 30 days which is also called sankramanam. Sun transits from meena (pisces) to mesha (aries) are called mesha sankramaNam. Similarly enters in taaurus is called vrushabha sankramanam and so on. 

12 Signs/Raashi are:

1. mesha – Aries                2. vrushabha – Taurus
2. mithuna – Gemini                      4. kataka/karkaataka – Cancer 
3. simha – Leo                            6. kanya– Virgo 
4. thula – Libra                             8. vrishchika – Scorpio 
5. dhanus – Sagittarius          10. makara – Capricorn 
6. kumbha – Aquarius  12. meena – Pisces 

paksha: There are two pakshas in each month; shukla paksha and krishna paksha.  shukla paksha consists of the bright half of the lunar month when the moon waxes.  The fifteen days from the next day of the amaavaasya to including paurnimaa constitute the shukla paksha. 

krishna paksha: The dark half of the lunar month or the other 15 days from the next day of the full moon to the new moon day make up the krishna paksha.

tithi: Total tithi are 30; 15 tithi in shukla paksha and 15 in krishna paksha.

 In shukla paksha it is

1. shukla paadyami 2. shukla dviteeya
2. shukla truteeya                                4. shukla chaturthi
3. shukla panchami 6. shukla shashti
4. shukla saptami                 8. shukla ashtami
5. shukla navami                 10. shukla dashami
6. shukla ekaadashi        12. shukla dwaadashi
7. shukla trayodashi       14. shukla chaturdashi & 
8. poornimaa  

In krishna paksha it is krishna paadyami to krishna chaturdashi & amaavaasya.  Tithi means the difference of 12 degrees from sun to moon is shukla paadyami, 24 degrees is shukla vidiya and 180 degrees is poornima. Similarly, the difference of 192 degrees is krishna paadyami, 204 degrees is krishna vidiya and 360 degrees is aamaavaasya.

vaara: According to soorya siddhaanta as per planet orbs the weekdays are formed. 

1. In planet orbs 4^th orb is sun kaksha, so first day is sunday/ravi vaasara. 
2. From sun to 4^th orb is chandra (moon) kaksha is monday/soma vaasara
3. next 4^th orb is mangala (kuja) – tuesday/mangala vaasara.
4. next 4^th orb is mercury/budha – wednesday/budha vaasara.
5. next 4^th orb is jupitor/guru – thursday/guru vaasara.
6. next 4^th orb is veenus – friday and shukra vaasara.
7. next 4^th orb is aaturn/shani – saturday/shani vaasara.

nakshatra: There are total 27 nakashatras(stars) in bhaachakram .  They are:

1. ashwini 2. bharani
2. krittikaa 4. rohini
3. mrigasheersha               6. aarudra
4. punarvasu               8. pushyami
5. aaslesha                                                 10. makha
6. poorva phalguni       12. uttara phalguni
7. hasta       14. chitta
8. swaati       16. vishaakhaa
9. anooraadhaa         18. jyeshtha
10. moola        20. poorvaashaadha
11. uttaraashaadha        22. shravanam
12. dhanishta        24. satabhisham
13. poorvabhaadra            26. uttarabhaadra
14. revati

Each nakshatra is 13°-20’ of arc and consists of 4 paadas. The Zodiac/raashi is circle of light, and it knows no beginning or end. To measure the distance an astronomical point (end of the constellation revati) is established which also happens to be first point of ashwini.