#include <math.h>#define IGREG (15+31L*(10+12L*1582))long julday(int mm, int id, int iyyy){	void nrerror(char error_text[]);	long jul;	int ja,jy=iyyy,jm;	if (jy == 0) nrerror("julday: there is no year zero.");	if (jy < 0) ++jy;	if (mm > 2) {		jm=mm+1;	} else {		--jy;		jm=mm+13;	}	jul = (long) (floor(365.25*jy)+floor(30.6001*jm)+id+1720995);	if (id+31L*(mm+12L*iyyy) >= IGREG) {		ja=(int)(0.01*jy);		jul += 2-ja+(int) (0.25*ja);	}	return jul;}#undef IGREG