Tithi ,yoga ,karan and nakshatra

Thithi (lunar day) :

Tithi is the date according to the Hindu lunar calendar. The Hindu lunar calendar consists of a dark and a bright fortnight also called Krishna paksha and Shukla Paksha. Tithi is said to be complete when moon has 12 degree from the sun. when moon complete 12 degree each time one tithi is comptete. There are 30 tithis in a lunar month. There are several rituals and festivals associated with Tithis. Most of the festivals fall on the new moon day (amavsaya) or the full moon day (poornma). It is important to note that starting or ending of a Tithi depends upon the degree of Moon from that of Sun therefore a Tithi ends or starts at any time in a day not like the Modern Time when a date changes at midnight.

There are 30 tithis in a lunar month. In Indian Astrology, the calculation of the Tithis starts from Pratipada (The first day in each half of the lunar month) of the Shukla-Paksha. Tithis are as follows :The Hindu Tithis are classified into 8 types:
Nanda Tithi – Bestows happiness, enjoyment.
Bhadra Tithi - Auspicious for stating new work
Jaya Tithi - Auspicious for winning over enemies.
Rikta Tithi – To be avoided for any important work.
Poorna Tithi – Auspicious to complete all jobs.
Dagdha Tithi--Inauspicious, fear of hurdles, obstructing the accomplishment of the work.
Visha Tithi--inauspicious, fear of hurdles, obstructing the accomplishment of the work.
Hutashan Tithi--inauspicious, fear of hurdles, obstructing the accomplishment of the work.2. Nakshatra:

Nakshatra Literally means “that which does not decay.” A group of stars is called Nakshatra. The whole space has been divided into 27 parts and each part has been given the name of Nakshatra. There are twenty-seven Nakshatras considered in Vedic Astrology. Each one of them has thirteen degree and twenty minutes of the zodiac. Each Nakshatra has a planetary lord used for Vimsottari Dasa and K.P. calculations. Nakshatra can be known with help of degrees of Moon in a particular sign at the time of birth. They are as follows :The Indian astrologers believe that the combination of the last 15 Ghati of 'Uttarashadha Nakshatra' and the first 4 Ghati of the Shravani Nakshatra i.e. 19 Ghatis in all, constitute the 'Abhijeet Nakshatra' and this particular Nakshatra is considered to be very auspicious to begin a good work.

PANCHAKA NAKSHATRA : The following group of five Nakshatras are considered as having five defects (Panchakadosha). They are Dhanistha, Shatabhisha, Purvabhadrapada, Uttarabhadrapada and Revati.

MOOLA NAKSHATRA : A child taking birth in this Nakshatra, which consists of Jyestha, Aashlesha, Revati, Mool, Magha and Ashwini Nakshatra are not considered as auspicious. Therefore, for the pacification of this 'Moola Nakshatra', some specific rites are performed 27th days after the birth when the same Nakshatra returns. Out of these six Nakshatras, which constitute Moola Nakshatra, Jyeshtha and Moola are called 'Gandant Moola' and Aashlesha is called as 'Sarpa Moola'.

ADHOMUKHA NAKSHATRA : As the name of this Nakshatra implies, works like digging a well, or lying a foundation is considered as auspicious. This particular Nakshatra is itself constituted by Nakshatras. They are: Moola, Aashlesha, Vishakha, Kritika, Purvaphalguni, Purvashadha, Purvabhadrapada, Bharani and Magha.

DAGDHA NAKSHATRA : For commencement of any work, these Nakshatras are considered as inauspicious. Therefore, commencing any work in this Nakshatra is prohibited if the days on which, this Nakshatra falls are as under-
Sunday - Bharani
Monday - Chitra
Tuesday - Uttarashadha
Wednesday - Dhanishtha
Thursday - Uttaraphalguni
Friday - Jyeshtha
Saturday – Revati

Nakshtra also indicate Yoni, Gana and Nadi of an individual.

Yoni: There are 14 Yonis (animal symbols) in Vedic astrology assigned to nakshtras are as follows :

Gana: There are 3 Ganas :
1. Deva: (Divine)
2. Manav: (Human)
3. Rakshas: (Demon)Nakshatras assigned to each Ganas are as follows:Nadi: There are 3 Nadis :
1. Adi: (Vata)
2. Madhya: (Pitta)
3. Antya: (Kapha or Shleshma)
Nakshatras assigned to each Nadi are as follows:3. Yoga:
A Yoga is obtained from the sum of the Nirayna Longitude of the Moon and Sun and the sum is divided into 27 parts of 13°20' each. There are 27 yogas :Ganda, Vyatipata, Atiganda, shoola are considered inauspicious yoga.

4. Karana:

Half of Tithi is called “Karana”. A Karana is completed when the Nirayana longitude of the Moon gains every 6° on that of Sun. There are 11 karanas in total. Four of them occur just once a month and are called the Fixed Karanas. The other seven are movable Karanas. They repeat 8 times starting from 2nd half of the first lunar day of a month.

Each of the Karana is said to have its own influence and interpretation. ‘Vishti’ is considered the most inauspicious karana. No important or new work is done during the period of this karana.

5. Vaar (day of the week) :

There are 7 days in a week. The days of the week along with the ruler planet are as follows :

The counting of days begins from the sunrise of the first day to the sunrise of the second day. In astrology, this system is known as 'AHORATRA', which means day and night taken together. Omitting the first letter 'A' and the last three letters 'T','R','A', the word 'HORA' is coined from which, the English word 'HOUR' originated. There are 24 HORAS in all.

GENTLE DAYS: Monday, Wednesday, Thursday and Friday are considered as the 'gentle' days. These days are considered auspicious for commencing any good work.

CRUEL DAYS: Tuesday, Sunday and Saturday are considered as 'cruel' days. Saturday is considered an auspicious day for undergoing operation. Thursday is considered auspicious for starting education. Wednesday is considered auspicious to start any business.