Our time systems are based on what is defined as the Local Hour Angle (LHA) of a celestial object. The LHA is the angular distance that a celestial object is from the observer's local meridian measured westward along the declination circle to the position of the object. Usually the object in question is the Sun, but the LHA of an object will tell the observer exactly where the object is relative to his/her local meridian, and therefore where to locate it in the sky.