include<stdio.h>

include<conio.h>

int main()
{
int fd,fm,fy,sd,sm,sy,ty,tday,rday,i,r,c1,c2;
printf("Entry Like Date<space>Month<space>Year\n");
printf("Enter Your 1st Date : ");
scanf("%d %d %d",&fd,&fm,&fy);
printf("Enter Your 2nd Date : ");
scanf("%d %d %d",&sd,&sm,&sy);
ty=fy-sy;
tday=ty*365;
tday--;
fy--;
for(i=sy;i<=fy;i++)
{
r=i%4;
if(r==0)
{
tday++;
}
}
c1=--fm;
switch(c1)
{
case 1:tday=tday+31;break;
case 2:tday=tday+59;fy++;r=fy%4;if(r==0){tday++;}break;
case 3:tday=tday+90;fy++;r=fy%4;if(r==0){tday++;}break;
case 4:tday=tday+120;fy++;r=fy%4;if(r==0){tday++;}break;
case 5:tday=tday+151;fy++;r=fy%4;if(r==0){tday++;}break;
case 6:tday=tday+181;fy++;r=fy%4;if(r==0){tday++;}break;
case 7:tday=tday+212;fy++;r=fy%4;if(r==0){tday++;}break;
case 8:tday=tday+243;fy++;r=fy%4;if(r==0){tday++;}break;
case 9:tday=tday+273;fy++;r=fy%4;if(r==0){tday++;}break;
case 10:tday=tday+304;fy++;r=fy%4;if(r==0){tday++;}break;
case 11:tday=tday+334;fy++;r=fy%4;if(r==0){tday++;}break;
}
tday=tday+fd;
c2=--sm;
switch(c2)
{
case 1:rday=31;break;
case 2:rday=59;r=sy%4;if(r==0){rday++;}break;
case 3:rday=90;r=fy%4;if(r==0){rday++;}break;
case 4:rday=120;r=fy%4;if(r==0){rday++;}break;
case 5:rday=151;r=fy%4;if(r==0){rday++;}break;
case 6:rday=181;r=fy%4;if(r==0){rday++;}break;
case 7:rday=212;r=fy%4;if(r==0){rday++;}break;
case 8:rday=243;r=fy%4;if(r==0){rday++;}break;
case 9:rday=273;r=fy%4;if(r==0){rday++;}break;
case 10:rday=304;r=fy%4;if(r==0){rday++;}break;
case 11:rday=334;;r=fy%4;if(r==0){rday++;}break;
}
rday=rday+sd;
tday=tday-rday;tday++;
printf("\nTotal Days : %d Days",tday);
getch();
}

#include "stdio.h"

int fy,fm,fd; //integers to hold first date
int sy,sm,sd; //integers to hold second date

/*in this i have assumed that first date is greater than second date*/

int oy,num_of_days,removed_days; //integers to hold the outputs

int i; //variable for 'for-loop'
int c1; //variable for first 'switch'
int c2; //variable for second 'switch'

int ex; //the exit sequence

char line[100]; //the input line

int main(){
printf("Please select a mode first\n");
printf("Enter 1 to do calculations.\n");
printf("Enter 0 to exit\n");

printf("Please Enter the dates in following oder\n");
printf("****Year****month**date**\n\n");

while(1){

//taking the mode or exit the program
printf("Please enter your need : ");
fgets(line,sizeof(line),stdin);
sscanf(line,"%d",&ex);

//the expressions to do the calculations
if(ex == 1){

//taking the first date
printf("Please enter the first date : ");
fgets(line,sizeof(line),stdin);
sscanf(line,"%d %d %d",&fy,&fm,&fd);

//taking the second date
printf("Please enter the second date : ");
fgets(line,sizeof(line),stdin);
sscanf(line,"%d %d %d",&sy,&sm,&sd);

oy = fy - sy; //taking the difference of the years
num_of_days = oy * 365; //setting output days

num_of_days--; //taking the extra day out

if(fy != sy)
fy--; //to take the last year before first_year


//taking the leap years between first and second year
for(i=sy;i<=fy;i++){

if(i%4 == 0)
num_of_days++;

}

if(fy != sy)
fy++; //setting first year value to previous value

//checking whether first year is leap, if it is then add one day
if(fy%4)
num_of_days++;

fm--;
c1 = fm;

//calculating the days of the first month
if(fm < 12){
switch(c1)
{
case 1 : num_of_days += 31; if(fy%4 == 0){num_of_days--;} break;
case 2 : num_of_days += 59; break;
case 3 : num_of_days += 90; break;
case 4 : num_of_days += 120; break;
case 5 : num_of_days += 151; break;
case 6 : num_of_days += 181; break;
case 7 : num_of_days += 212; break;
case 8 : num_of_days += 243; break;
case 9 : num_of_days += 273; break;
case 10 : num_of_days += 304; break;
case 11 : num_of_days += 334; break;
}
}

//throwing exception for invalid dates
else{
printf("Error : Enter valid date\n");
continue;
}

num_of_days += fd; //adding the days of the first date

c2 = --sm;

//calculating the days of the second month
if(sm < 12){
switch(c2)
{
case 1 : removed_days += 31; if(sy%4 == 0){removed_days--;} break;
case 2 : removed_days += 59; break;
case 3 : removed_days += 90; break;
case 4 : removed_days += 120; break;
case 5 : removed_days += 151; break;
case 6 : removed_days += 181; break;
case 7 : removed_days += 212; break;
case 8 : removed_days += 243; break;
case 9 : removed_days += 273; break;
case 10 : removed_days += 304; break;
case 11 : removed_days += 334; break;

}
}
//throwing exceptions for invalid days
else{
printf("Error : Enter valid date\n");
break;
}
removed_days += sd;

//checking whether second year is leap
if(sy%4 == 0)
removed_days++;

//calculating the number of days
num_of_days = num_of_days - removed_days;

printf("There are %d days between %d-%d-%d and %d-%d-%d.\n",
num_of_days,fy,++fm,fd,sy,++sm,sd);
ex = 0; //to change the exiting status
continue;
}

//the exit
else if(ex == 0){

printf("Thank you for using this service.\n");
break;

}

//the expression to eveluate wrong modes
else{

printf("Please enter a valid mode.\n");
continue;

}

}


return(0);
}