This routine computes the approximate sunrise and sunset times given the site coordinates and the declination angle, previously computed as part of the solar position equation.

Inputs

Outputs

 

Algorithm

1.) Find the sunrise and sunset times assuming the standard refraction of the sun at the horizon with the midpoint
of the solar disk about 0.833° below the horizon.

2.) Find the sunrise and sunset solar times.

 

3.) Convert from solar to local time by subtracting the equation of time difference instead of adding it.

 

References

http://www.srrb.noaa.gov/highlights/sunrise/solareqns.PDF