This Sun Position Calculator will forecast the billet of the bottom and top of the SunВґs rim, sunset and dayspring time at any geographical positioning (characterized by observational height, latitude and longitude) at any date (between 1900- 2100) and time. SPC will also argue the dusk or when the Sun is not visible. A defer with latitudes and longitudes, and GMT+ for some major cities approximately the humanity is incorporated. The SunВґs billet is characterized by the elevation lean relative to the horizon and azimuth relative to the North instruction. Since the observed billet of the Sun buns be effected by the refraction of the light rays in the atmosphere (especially for depleted elevation angles), the programme gives both the real billet of the Sun (without atmospheric refraction) and the observed elevation and azimuth (when atmospheric refraction is accounted). The same remarks are valid for sunset and dayspring time. Atmospheric refraction is taken into describe in a more realistic manner, than in other available Sun Position Calculators. We compute the refraction corrections by using a Standard Atmosphere modeling. In place to coming a realistic atmosphere profile the programme needs as input the expected temperature and pressure for an arbitrary chosen altitude. To manipulation and install SPC, download spc.hurry and unzip it on your computer. The directory SPC will be created, with four files in it: "SPC.exe", "LatLonGMT.chm", "SPC.ini" and "SPCHelp.chm". The file "SPC.exe" is the executable, and the other three files are databases and texts used forthwith by SPC.exe. "LatLonGMT.chm" is a database with Latitudes, Longitudes and GMT+ for some major cities and countries approximately he humanity, "SPCHelp.chm" is the help-file and "SPC.ini" is a file in which the programme remembers the last input parameters. The programme runs by launching "SPC.exe". Authors: Sandor Volkan-Kacso and Zoltan Neda s.