Altair is an astronomy calculator for Windows. Altair calculates Local Sidereal Time, Julian Date, Universal Time, RA/DEC to Alt/Az and Alt/Az to RA/DEC. Built in object database. Built in location database. Converts RA/DEC to Alt/Az and Alt/Az to RA/DEC. Calculates Julian Date. Calculates Local Sidereal Time. Calculates Universal Time. Print Results. Write to Text File. Enter any date between 1900 and 2100.