Panchangam (Hindu astrological almanac)
Pangangas are published in India by many learned authors, societies, academies and universities. Different publications differ only minutely, at least for a casual or un-trained reader. They forecast celestial phenomena such as solar eclipses, forecast weather (rain, dry spells) as well as more mundane occurrences. Panchangas are used in Jyothisham
The study of Panchangas involves understanding Raashi phala, the impact of the Signs of the zodiac on the individual. Astrologers consult the Panchangam to set auspicious dates for weddings, House warming, and other worldly activities as per religion.
The actual casting of Panchangam involves elaborate mathematical work involving high level of spherical geometry and sound understanding of astronomical phenomena, such as sidereal movements of heavenly bodies. However, in practice the tabulation is done on the basis of short-cut formulations as propounded by ancient Vedic sages and scholars.
A typical Panchangam may state tabulations of positions of Sun, Moon, and other planets for everyday of the year on a fixed place (longitude, latitude) and time of the day. The users calculate the remaining data using their relative difference from this fixed place and time.
The government of India has prepared the National Panchangam or the Indian National calendar in 1957 (was proposed by Saha and Lahiri in 1952), which is used in predictive astrology. The Lahiris Ephemeris published annually is the most widely used English almanac in Vedic astrology apart from the many Pangangas published in local languages, which are mostly based on the National Panchangam.
Meaning of Panchangam in Vedic astrology is the five attributes of the day. They are:
Tithi- Ending Moment of elongation of the Moon, the lunar day, the angular relationship between Sun and Moon (Apparent Moon –Apparent Sun). One Tithi equals 12 degree difference between Moon and Sun
Nakshatra: Ending Movement of asterism of the day, i.e. stellar mansion in which Moon is located for an observer at the center of the Earth. One Nakshatra equals 13 degrees: 20 Minutes. There are 27 Nakshatra in 360 degrees.
Yoga: Ending Moment of the angular relationship between Sun and Moon (Apparent Moon + Apparent Sun). One Yoga equals 13 degrees; 20 Minutes. There are 27 Yogas in 360 degrees.
Karanam: Ending Moment of half of a Tithi. One Karanam equals 6 degree difference between Moon and Sun.
Varam: Weekday the seven weekdays.An Almanac that contains the astronomical/astrological daily details also come to be called a Panchangam because of the importance of five attributes.