Time. Converting the date to DAYS -- Converting hours, minutes and seconds to decimal hours -- Converting decimal hours to hours, minutes and seconds -- Converting the local time to GMT(UT) -- Sidereal time (ST) -- Conversion of GMT to GST -- Conversion of GST to GMT -- Local sidereal time -- Coordinate system. Horizon coordinates -- Equatorial coordinates -- Ecliptic coordinates -- Galactic coordinates -- Converting between decimal degrees and degrees, minutes and seconds -- Converting from right ascension to hour-angle -- Equatorial to horizon coordinate conversion -- Horizon to equatorial coordinate conversion -- Ecliptic to equatorial coordinate conversion -- Equatorial to ecliptic coordinate conversion -- Equatorial to galactic coordinate conversion -- Galactic to equatorial coordinate conversion -- Rising and setting -- Precession -- Refraction -- The sun. Orbits -- The apparent orbit of the sun -- Calculating the position of the sun -- Calculating orbits more precisely -- Calculating the sun's distance and angular size -- Sunrise and sunset -- The equation of time -- Solar elongations -- The planets and comets. The planetary orbits -- Calculating the coordinates of a planet -- Finding the approximate positions of the planets -- The angular sizes and the distances of the planets -- The phases of the planets -- The apparent brightness of a planet -- Comets -- The moon and eclipses. The moon's orbit -- Calculating the moon's position -- The moon's hourly motions -- Moonrise and moonset -- The phases of the moon -- The moon's distance, angular size and parallax -- Eclipses -- The 'rules' of eclipses -- Calculating a lunar eclipse -- Calculating a solar eclipse