C Tutor... C Tutorial....: Program to find your Day of Birth given Date of Birth

#include
#include "stdlib.h"
#include "conio.h"

main()
{
clrscr();
int d,m,y,year,month,day,i,n;
printf("Enter how many times you want to run this program : ");
scanf("%d",&n);
for(i=1;i<=n;i++)  {  printf("  Enter the date :    ");  scanf("%d%d%d",&d,&m,&y);  if( d>31 || m>12 || (y<1900>=2000) )
 {
  printf("INVALID INPUT");
  getch();
  exit(0);
 }
year = y-1900;
year = year/4;
year = year+y-1900;
switch(m)
 {
  case 1:
  case 10:
           month = 1;
           break;
  case 2:
  case 3:
  case 11:
           month = 4;
           break;
  case 7:
  case 4:
          month = 0;
          break;
  case 5:
          month = 2;
          break;
  case 6:
          month = 5;
          break;
  case 8:
          month = 3;
          break;
  case 9:
  case 12:
          month = 6;
          break;
 }
year = year+month;
year = year+d;
day  = year%7;
switch(day)
 {
  case 0:
          printf("Day is SATURDAY");
          break;
  case 1:
          printf("Day is SUNDAY");
          break;
  case 2:
          printf("Day is MONDAY");
          break;
  case 3:
          printf("Day is TUESDAY");
          break;
  case 4:
          printf("Day is WEDNESDAY");
          break;
  case 5:
          printf("Day is THURSDAY");
          break;
  case 6:
          printf("Day is FRIDAY");
          break;
 }
}
getch();
return 0;
}

Related Links :

History Of C..

In the beginning was Charles Babbage and his Analytical Engine, a machine
he built in 1822 that could be programmed to carry out different computations.
Move forward more than 100 years, where the U.S. government in
1942 used concepts from Babbage’s engine to create the ENIAC, the first
modern computer.
Meanwhile, over at the AT&T Bell Labs, in 1972 Dennis Ritchie was working
with two languages: B (for Bell) and BCPL (Basic Combined Programming
Language). Inspired by Pascal, Mr. Ritchie developed the C programming
language.