include stdint include math define tl_hour define tl_minute define tl_

#include <stdint.h>
#include <math.h>

#define tl_hour 0
#define tl_minute 1
#define tl_second 2
#define tl_day 3
#define tl_month 4
#define tl_year 5

// Часы, Минуты, Секунды, Число, Месяц, Год
uint16_t dt[] = {0, 0, 0, 5, 5, 2019};
// Широта и долгота
float latitude=55.708102, longitude=36.794008;
// Часовая зона в минутах (часы * 60)
int timezone=3*60;

uint8_t ComputeSun(uint8_t rs);
int main()
{
  ComputeSun(1); // Восход
  ComputeSun(0); // Заход
  return 0;
}
uint8_t IsLeapYear(int yr){
	return ( (yr % 4 == 0 && yr % 100 != 0) || yr % 400 == 0);
}
uint8_t LengthOfMonth(uint16_t * when){
	uint8_t odd, mnth;
	int yr;
        yr=when[tl_year]+2000;
	mnth=when[tl_month];
	if(mnth==2){
		if(IsLeapYear(yr) ) return 29;
		return 28;
	}
	odd=(mnth & 1) == 1;
	if (mnth > 7) odd  = !odd;
	if (odd) return 31;
	return 30;
}
int Absolute(int n){
	if(n<0) return 0-n;
	return n;
}
char Signum(int n){
	if(n<0) return -1;
	return 1;
}
long DayNumber(uint16_t y, uint8_t m, uint8_t d){
	m = (m + 9) % 12;
	y = y - m/10;
	return 365*y + y/4 - y/100 + y/400 + (m*306 + 5)/10 + d - 1 ;
}
void Adjust(long offset){
	long tmp, mod, nxt;
	// offset is in minutes
	tmp=dt[tl_minute]+offset; // minutes
	nxt=tmp/60;				// hours
	mod=Absolute(tmp) % 60;
	mod=mod*Signum(tmp)+60;
	mod %= 60;
	dt[tl_minute]=mod;
	tmp=nxt+dt[tl_hour];
	nxt=tmp/24;					// days
	mod=Absolute(tmp) % 24;
	mod=mod*Signum(tmp)+24;
	mod %= 24;
	dt[tl_hour]=mod;
	tmp=nxt+dt[tl_day];
	mod=LengthOfMonth(dt);
        dt[tl_day] = tmp;
	if(tmp>mod){
            while (tmp>mod) {
		tmp -= mod;
		dt[tl_month]++;
                if (dt[tl_month] > 12) {
                    dt[tl_month] = 1;
                    dt[tl_year]++;
                    dt[tl_year] += 100;
                    dt[tl_year] %= 100;
                }
                mod = LengthOfMonth(dt);
            }
            dt[tl_day]=tmp;
	} else if (tmp<1) {
            while (tmp<1) {
		dt[tl_month]--;
                if (dt[tl_month] < 1) {
                    dt[tl_month] = 12;
                    dt[tl_year] --;
                    dt[tl_year] += 100;
                    dt[tl_year] %= 100;
                }
		mod=LengthOfMonth(dt);
		dt[tl_day]=tmp+mod;
                tmp += mod;
            }
	}
}
uint8_t ComputeSun(uint8_t rs) {
  uint8_t  month, day;
  float y, decl, eqt, ha, lon, lat;
  uint8_t a;
  int minutes;
  month=dt[tl_month]-1;
  day=dt[tl_day]-1;
  lon=-longitude/57.295779513082322;
  lat=latitude/57.295779513082322;
  //approximate hour;
  a=6;
  if(rs) a=18;
  // approximate day of year
  y= month * 30.4375 + day  + a/24.0; // 0... 365
  // compute fractional year
  y *= 1.718771839885e-02; // 0... 1
  // compute equation of time... .43068174
  eqt=229.18 * (0.000075+0.001868*cos(y)  -0.032077*sin(y) -0.014615*cos(y*2) -0.040849*sin(y* 2) );
  // compute solar declination... -0.398272
  decl=0.006918-0.399912*cos(y)+0.070257*sin(y)-0.006758*cos(y*2)+0.000907*sin(y*2)-0.002697*cos(y*3)+0.00148*sin(y*3);
  //compute hour angle
  ha=(  cos(1.585340737228125) / (cos(lat)*cos(decl)) -tan(lat) * tan(decl)  );
  if(fabs(ha)>1.0){// we're in the (ant)arctic and there is no rise(or set) today!
  	return 0; 
  }
  ha=acos(ha); 
  if(rs==0) ha=-ha;
  // compute minutes from midnight
  minutes=(int) (720+4*(lon-ha)*57.295779513082322-eqt);
  // convert from UTC back to our timezone
  minutes+= timezone;
  // adjust the time array by minutes
  dt[tl_hour]=0;
  dt[tl_minute]=0;
  dt[tl_second]=0;
  Adjust(minutes);
  return 1;
}