For all those, who want to use the implementation after year 2015, the sidereal and solar data should be updated (see http://www.amsat.org/articles/g3ruh/111.html end of code).
Change the lines 41..49 in P13.h to
static const double YG = 2014.f;
static const double G0 = 99.5828f;
static const double MAS0 = 356.4105f;
static const double MASD = 0.98560028f;
static const double EQC1 = 0.03340;
static const double EQC2 = 0.00035;
static const double INS = radians(23.4375f);
Solar data is valid until ~2030
For all those, who want to use the implementation after year 2015, the sidereal and solar data should be updated (see http://www.amsat.org/articles/g3ruh/111.html end of code).
Change the lines 41..49 in P13.h to
Solar data is valid until ~2030