Panchanga or the almanac is an important tool for keeping track of various celestial objects. So far, we've seen some important units of time, like years, months, etc. A Panchanga deals with these and many other units of time and relates them with one another. Moreover, the position of various objects like the sun, moon and the planets, the rising times of Sun and the Moon etc., are given in a Panchanga. How are the positions of the heavenly bodies measured?Click here to find out . The Panchangas are published at various places since some values like the rising time of the Sun, etc., are place dependent. It is essential that you have some knowledge in Indian Panchanga, because it is something like a geometry set for your geometric constructions.
The Panchanga for a given year will first give the name of the year and the number of years that have been completed starting from an 'epoch' (some suitable instant of time). The Indian Panchanga apart from giving statistical values also gives astrological information like auspicious moments, dates for religious festivals, etc.
Now, what is the Panchanga made up of? Panchanga, as the name denotes, is made up of 5(pancha) parts (angas). They are,
- Vaara (of course the weekday)
- tithi (It is not 'day', mind you. )
- Karana (You better know whats a tithi first, because this is half a tithi)
- Nakshatra (The same old nakshatra)
- Yoga (Just read through to find out )
You must be familiar with the term Vaara. Vaara is the day of the week. The weekdays are Ravi (Sunday), Soma (Monday), Mangala (Tuesday), Budha (Wednesday), Guru or Brihaspati (Thursday), Sukra (Friday), Sani (Saturday) named after Sun, moon, Mars, Mercury, Jupiter, Venus, Saturn respectively. According to our tradition, these heavenly bodies are supposed to be the presiding deities on the days named after them.
You might have heard this term used by many priests. What indeed is a tithi? We've already defined a lunar month as the time taken for the separation between the Sun and the Moon to increase by 360º. We define a tithi to be the time taken for the separation between the Sun and the Moon to increase by 12º. This means that a tithi is one-thirtieth of a Lunar month. So you can consider it as a Lunar day. Let us have a look at the names of the tithis. But the duration of each tithi may vary because of the non-uniform motion of the Moon. The tithi corresponding to a particular Solar day is defined as that tithi which is present at sunrise. It may so happen that a tithi starts after a sunrise and ends before the next sunrise. So, that tithi will be skipped. It is also possible that a tithi starts just before surise and ends just after the next sunrise. So, in this case two days will have the same tithi!
How to find the tithi corresponding to a particular day? For a given day, find out the celestial longitude of the Sun and the Moon. The difference between them will give you the angular separation between them. If you divide this difference by 12, you'll get the no. of tithis elapsed since Amavasya. Thus,
Number of tithis completed = (celestial longitude of moon - celestial longitude of sun)/12 (with 360° added to celestial longitude of the moon to make it greater than that of the sun).
The current tithi is this quantity plus one.
Let us consider an example: On January 1,1992, at 5:30am IST, the longitude of the moon and the sun are 212° 24' and 256° 3' 13'' respectively. Find the tithi.
Longitude of the moon = 212° 24'
Longitude of the sun = 256° 3' 39''
Difference = ((212° 24' + 360° ) - 256° 3' 39'')/12° = 26
Therefore the current tithi is 26 + 1 = 27th tithi from Amavasya.
Karana is half a tithi. So a lunar month will have 60 karanas. There are only 11 names available for the karanas-
- seven chara (movable) karanas, viz., Bava, Baalava, Kaulava,
Taitila, Gara, Vanija and Vishti
- four sthira (immovable) karanas, viz., Sakuni, Chatushpada, Naaga and Kimstughna.
These karanas occur in a particular order every month. The first half of the sukla paksha prathama (the first tithi of the Sukla paksha) is Kimstughna and the second half is the bava. The next karanas are the chara karanas, namely, baalava, kaulava etc. upto Vishti. These sets of seven Karanas repeat 8 times. So we have covered 1 +(7*8)=57 karanas. The 58th karana, corresponding to the 29th tithi of the month, is named sakuni. The next karana is the chatuspada (1st half of amavasya) and the last karana of any lunar month is the naaga.
The nakshatra division occupied by the moon at a particular day gives the nakshatra corresponding to that day. Recall that a Nakshatra division is obtained by dividing the circle of Moon's revolution by 13° 20' (360/27), so that we get 27 Nakshatra divisions. The starting and the ending moment of a nakshatra are given in the Panchangas. The number of nakshatras elapsed can be calculated from the Nirayana longitude of the moon as follows,
The number of nakshatras that have elapsed = Nirayana longitude of the moon at that instant / 13° 20'
Yoga is yet another term present in Panchangas. The number of yogas completed at any time is calculated as the sum of the Nirayana longitudes of the Sun and the moon. If this sum exceeds 360°, then subtract 360°. This value is divided by 13° 20' (which is 1/27 th of a full revolution). The current yoga is given by adding 1 to the completed number of yogas. There are 27 yogas and they are:
1.Viskumbha 2.Preeti 3.Aayusman 4.Sowbaghya 5.Sobhana 6.Atiganda 7.Sukarma 8.Dhruti 9.Sula 10.Ganda 11.Vriddhi 12.Dhruva 13.Vyaghatta 14.Harshana 15.Vajra 16.Siddhi 17.Vyatipatta 18.Variyan 19.Parigha 20.Siva 21.Siddha 22.Sadhya 23.Subha 24.Sukla 25.Brahma 26.Indra 27.Vadhriti
These values are there in the Panchanga because, it is very essential to have an accurate knowlede of the longitude of the sun and the moon to determine the beginning and ending moments of a solar month, lunar month, tithi, karana, nakshatra and yoga. Looking at it the other way, knowing these values gives the position of various celestial objects. Its enough for now to know that many such ingenious and simple methods were evolved in Indian astronomy to calculate the longitudes of the sun, the moon and the planets and that these procedures were improvised from time to time.
Apart from all these values the Panchanga also contains Lagnas (alternative for time) and Muhurtas. Let us see what they are.
We've seen about the twelve Rasis, which correspond to the division of the Zodiac into 12 zones. Lagna is closely related to Rasis. At any instant of time, the Lagna is given by the Rasi, which is just above the horizon. Let us make it a bit clearer. In a particular day, suppose a particular star rises in the eastern sky at 6:00. Find out the Zodiacal division or Rasi corresponding to that star. The Lagna at that time, corresponds to the Rasi of that star. In the panchangas, the beginning moment of each lagna (Mesha, Vrishabha,...) on any particular day is given. The durations of the different lagnas are different because of the inclination of the ecliptic to the equator. Again the instant corresponding to the beginning of each lagna would be different for places with different latitudes.
Each solar day consists of 30 muhurtas or 60 ghatikas. So the duration of a muhurta comes to 48 minutes, and that of a Ghatika is 24 minutes.