C program for date validation.

#include<stdio.h>

#include<conio.h>

void main() {

int dd,mm,yyyy,md,flag=1;

clrscr();

printf("Enter dd/mm/yyyy\n");

scanf("%d%d%d",&dd,&mm,&yyyy);

switch (mm) {

case 1: case 3: case 5: case 7: case 8: case 10: case 12: 

md=31; break;

case 4: case 6: case 9: case 11: 

md=30; break;

case 2: 

if (yyyy%4==0) 

md=29;

else md=28; 

break;

default: flag=0;

printf("\nInvalid month%d\n",mm);

}

if (flag==1) {

if (yyyy>=1900 && yyyy<=2100) {

if (dd>=1 && dd<=md)

printf("\nGiven date %d/%d/%d is vaid date\n",dd,mm,yyyy);

else printf("\nInvalid day %d\n",dd);

}

else printf("%d is not in given year range 1900 to 2100\n",yyyy);

}

getch();

}