Panchang - Calculation of Tithi

A Tithi is a lunar day after the conjunction of Sun & Moon. When Sun and Moon have equal longitude and there is no distance between the two, there is zero lithi. The time taken by Moon to go ahead of Sun by 12 degree is the period of 1 Tithi. The average time of a Tithi is 23H 37M 28S
A tithi is an exact lunar day, which is approximately one-thirtieth of the time it takes the moon to orbit the earth.
Tithis vary in duration from approximately 19 to 26 hours, according to the movement of the Moon. Each Tithi has a name, a ruling planet, and can be used in Muhurta (picking a proper time).Amavasya is when the Sun and Moon's longitude is the same again.

 There are 15 tithis in the waxing cycle of the moon (shukla paksha), and there are 15 tithis in the waning cycle of the Moon ( Krishna paksha). The tithi is based on a relationship between the Sun and the Moon. The first tithi is 12 degrees of the Moon away from the Sun after the new Moon (Amavasya) or full Moon (Purnima). The second tithi is the next 12 degrees of the Moon away from the Sun, 12 to 24 degrees. A particular day is ruled by the tithi at sunrise, but the tithi can change anytime of the day or night as it is not based on the solar day.

Formula to calculate Tithi: 

Longitude of Moon –Longitude of Sun 

12

13 Apr 2014

Longitude of Moon 5s- 3-49

Longitude of Sun 11s 29-10

(153-49)- (359-10) 

12

Adding 360 to longitude of Moon153.49+360=513.49

:. (513-49)- (359-10) 

12

Quotient =12 so Tithi on 13 april 2014 is 12+1 i.e. Triyodashi  Tithi

Tithi	Phase difference between Sun & Moon
	Shukla Paksh	Krishna Paksh
Prathma or Pratipada	12°×1=12°	180° + 12°×1=192°
Dvitiya	12°×2=24°	180°+12°×2=204°
Tritiya	12°×3=36°	180°+12°×3=216°
Chaturthi	12°×4=48°	180°+12°×4=228°
Panchami	12°×5=60°	180°+12°×5=240°
Shashthi	12°×6=72°	180°+12°×6=252°
Saptami	12°×7=84°	180°+12°×7=264°
Ashtami	12°×8=96°	180°+12°×8=276°
Navami	12°×9=108°	180°+12°×9=288°
Dashami	12°×10=120°	180°+12°×10=300°
Ekadashi	12°×11=132°	180°+12°×11=312°
Dvadashi	12°×12=144°	180°+12°×12=324°
Trayodashi	12°×13=156°	180°+12°×13=336°
Chaturdashi	12°×14=168°	180°+12°×14=348°
Poornima / Aamavasya	12°×15=180°	180°+12°×15=360° or 0°

The lunar days (Tithis) of both the bright and dark half of the month are below:

Day	Tithi	Quality	Deity
One	Pratipada	One Giving Rise	Agni
Two	Dwitiya	Auspicious	Ashwini Kumar/Brahma
Three	Tritiya	Strength & Power	Gauri - Wife of Shiva
Four	Chaturthi	Negative	Ganapati
Five	Panchami	Lakshmi /Wealth	Naga
Six	Shashti	Fame	Kartika-Mars
Seven	Saptami	Friendly	Surya - Sun
Eight	Ashtami	Conflict	Shiva / Matrgana
Nine	Navami	Aggressive	Durga
Ten	Dashami	Soft	Yama - the God of Death/Diks - Godesses of the Ten Directions
Eleven	Ekadashi	Happiness	Vishwedeva / Kuber /Vayu
Twelve	Dwadashi	Fame	Vishnu
Thirteen	Triyodashi	Victory	Kamdeva / Dharma
Fourteen	Chaturdashi	Aggressive	Shiva/ Rudra
Fifteen/Full Moon	Purnima	Soft	Soma
Thirtieth	Amavasya	Inauspicious	Pitris

The rulership of the Tithis is based on the days of the week;

Planet	Tithi	Tithi
Sun	1	9
Moon	2	10
Mars	3	11
Mercury	4	12
Jupiter	5	13
Venus	6	14
Saturn	7	15
Rahu	8	0

Tithis are also broken down into five groups given below:

The Tithis are divided into five groups:

   1. Nanda (Ananda or Joyous) Tithis - Pratipada (1st), Shashti (6th) and Ekadashi

(11th) bestows happiness and joy

   2. Bhadra (Arogya or Mangala or Healthy) Tithis - Dwitiya (2nd), Saptami (7th) and Dwadashi (12th) good for stating new work

   3. Jaya (Victory) Tithis -Tuesday Tritiya (3rd), Ashtami (8th) and Triyodashi

(13th) good for winning over enemies

  4. Rikkta (Loss or Nashta) Tithis - Saturday Chaturthi (4th), Navami (9th) and

Chaturdashi (14th) not good for any important work, so it is avoided

  5. Poorna (Sambora - Full Moon or New Moon) Tithis -Thursday Panchami

(5th), Dashami (10th) and Amavasya (15th)(New Moon) or Purnima (15th) very good to complete all jobs

Nanda	Fire	1, 6, 11	Friday
Badra	Earth	2, 7, 12	Wednesday
Jaya	Akash	3, 8, 13	Tuesday
Rikta	Water	4, 9, 14	Saturday
Purna	Vayu	5, 10, 15	Thursday

Here Trittya Tithi (3rd) is ruled by Mars but as it is Jaya (ruled by akash/Jupiter) so it will bring two people together, as akash is the binding force (that keeps the jiva in the body). Ekadasi Tithi (11th) is ruled by Mars and it is Nanda (ruled by fire-Mars) so the fighting is very strong. Mars is passionate, energetic, and creates conflict, it is not good for marriage, though it is good for war and leadership.

When certain Tithis line up with specific Varas (days) they are considered auspicious and therefore work on those days is accomplished successfully.

If Pratipada (1st), Shashti (6th), or Dwadashi (12th) fall on a Friday, it is considered auspicious

Types of Tithi

There are several types of Tithi. To know the auspicious Tithi one must know about them.

A-Khand Tithi (undivided) 

When one Tithi continues from sunrise to sunset, it is called "A-Khand (undivided) Tithi"

Khandit Tithi (divided) 

When any Tithi ends before sunset it is called "Khandit (divided) Tithi"

Kshaya Tithi (destructive) 

If there are three Tithi in one day, it is called (Tithi is destructed).....  Not good

Example of vridhi Tithi:

9 April 2014

Time of sunrise on 9 April 2014: 6.08

Time of sunrise on 10 April 2014: 6.06

.	Longitude of Moon	Longitude of Sun
10 April 2014 at 5.30am	3s-24-51-57	11s-25-59-30
9 April 2014 at 5:30 am	3s-12-57-05	11s-25-00-14
Motion in 24 hours	0s-11-54-52	0s-59-00-16
Motion in (6.08-5.30) 38 min	0s-00-18-56
10 April 2014 at 6:08	3s-25-09-53	11s-26-01-17
09 April 2014 at 6:08	3s-13-15-54	11s-25-02-26

Tithi on 9 April 2014 :( (463-16-54)- (355-02-26)

                            12

Q=9

So Tithi in progress=Dashmi

Tithi on 10 April @sunrise:

(475-09-53)- (356-01-36)

  12

Q = 9

Shows dashmi tihi still in progress (Tithi Vridhi)

Anju Anand

To be conti………