Convert from spat to parasang

Unit Definition (spat)
The spat is an informal unit of distance formerly used by astronomers. The spat is equal to the terameter (Tm, or 10E12 meters). This is equivalent to about 6.6846 astronomical units. The origin of this usage is not clear; "spat" may be an acronym for "space unit" or "space-time".

Unit Definition (parasang)
The parasang (Persian - farsang) is an ancient Persian unit of itinerant distance corresponding to approximately 3.5 miles (5.6 kilometers)., or the distance that can be traversed on foot in an hour.