Compensate for the equation of time and get the local solar time!
Install by cding to the repository and make then make install (with root privileges).
Use with solar_time.
The 5 sines and cosines approximation used is from (Lamm, 1981), with an average error of 0.63 seconds over one year and a maximum absolute error of 2.0 seconds.
See this page from powerfromthesun.net for details on the calculation.