Day of the Week by Zeller's Congruence

//h= [ q + floor(13*(m-1)/5) + floor(k/4) + floor(j/4) + 5*j ] % 7
#include <stdio.h>
#include <math.h>
int main()
{
  int h,q,m,k,j,day,month,year;
  printf("Enter the date (dd/mm/yyyy)\n");
  scanf("%i/%i/%i",&day,&month,&year);
  if(month < 3)
  {
    month += 12;
    year--;
  }
  q = day;
  m = month;
  k = year % 100;
  j = year / 100;
  h = q + floor(13*(m+1)/5) + k + floor(k/4) +  floor(j/4) + 5 * j;
  h = h % 7;
  switch(h)
  {
    case 0 : printf("Saturday.\n"); break;
    case 1 : printf("Sunday.\n"); break;
    case 2 : printf("Monday. \n"); break;
    case 3 : printf("Tuesday. \n"); break;
    case 4 : printf("Wednesday. \n"); break;
    case 5 : printf("Thurday. \n"); break;
    case 6 : printf("Friday. \n"); break;
  }
  fflush(stdin);
  getchar();
  return 0;
}