A Panchang calendar is a traditional Hindu astrological calendar, which is based on the traditional Indian astrological concepts. It shows important astronomical information in a tabular form.
Panchang calendar was published by a number of Indian scholars and learned men based on planet and star movement and positions. These are used to forecast solar and lunar eclipses, weather conditions and other day to day events as well. Along with the planets and stars, study of a Panchang calendar also includes detailed understanding of the zodiac sign or Raashiphala and its impact. The Panchang helps to set out auspicious dates for a number of daily as well as religious events.
It is made using complex mathematical calculations using spherical geometry and deep understanding of the astronomical aspects, like movements of the astronomical bodies. A typical panchang shows tabulated information on the position of the sun, moon and planets for every single day of the year, for a specific location and time of day. There are some panchang that show information relevant for more than one year. One such panchang is Vishvavijaya Panchang which is for a hundred years. The basic use of the Panchang calendar is prediction of all the important festivals, events, dates, auspicious/inauspicious time.
The Government of India has got made the national Panchang calendar which is used to make various predictions for important national events and dates. The panchang named Lahiris Ephemeris is currently the most popularly used English astrological calendar which is based on Vedic astrology, apart from the other panchang of local languages which are mainly based on our national panchang.