Calender Project in C++

//Program for Calendar of 700 years(1700-2400)
#include<iostream>
#include<conio.h>
#include <ctime>
#include<Windows.h>
using namespace std;
void heading(char ch, int i)
{
int j;
for (j = 0; j <= i; j++)
cout << ch;
}
void Start_up()
{
char ch[30] = "Wellcome to 131362 Project\n";
cout << "\t\t\t";
for (int i = 0; i < 30; i++)
{
Sleep(150); cout << ch[i];
}
for (int i = 0; i <= 79; i++)
{
Sleep(30); cout << "\xDB";
}
system("cls");
}
class calender
{
private:
int date, month,year;
public:
calender(int d = 1, int m = 1, int y = 1700) // constructor
{
date = d;
month = m;
year = y;
}
void day(int); // name of a specific day
void monthcal(int,int); // for printing specific month's calender
bool leapyear(int); // condition for leapyear
int DaysInMonth(int,int); // number of days in each month
int DayNumber(int,int,int); // total number of days passed from January 1, 1583 to current day.

};
bool calender :: leapyear(int y)
{
bool Leap;
if ((y % 4 == 0) && ((y % 100 != 0) || (y % 400 == 0)))
Leap = true;
else
Leap = false;
return Leap;
}
int calender :: DaysInMonth(int m, int y)
// m is the month number (1,2,3,...12), y is the year number (four digits)
{
switch (m)
{
case 1:
case 3:
case 5:
case 7:
case 8:
case 10:
case 12: return 31;
case 2: if (leapyear(y))
return 29;
else
return 28;
default: return 30;
}
}
int calender :: DayNumber(int d, int m, int y)
{
int i;
int dow = 6;
for (i = 1583; i<y; i++)
// In the Gregorian Calendar, January 1, 1583, was a Saturday, so we will start with 6
{
dow += (leapyear(i)) ? 2 : 1;
dow+=364;
}
for (i = 1; i<m; i++)
dow += DaysInMonth(i, y);
dow += d;
return dow;
}
void calender::day(int a)
{
switch (a)
{
case 1:
cout << "Monday";
break;
case 2:
cout << "Tuesday";
break;
case 3:
cout << "Wednesday";
break;
case 4:
cout << "Thursday";
break;
case 5:
cout << "Friday";
break;
case 6:
cout << "Saturday";
break;
case 0:
cout << "Sunday";
break;
default:
cout << "\a\a\a\n\nERROR!!!"; //Exceptional cases and bugs if present
}
}
void calender::monthcal(int month, int year)
{
int j, mon, c;
j = 0;
for (j = 0; j <= 6; j++) // For printing 7 days of week
{
day(j);
cout << " ";
}
j = 1;
c = DayNumber(--j, month, year);
c=c%7;
cout << "\n";
switch (c) //position of 1st date of month
{
case 0:
break;
case 1:
cout << "\t";
break;
case 2:
cout << "\t\t";
break;
case 3:
cout << "\t\t\t";
break;
case 4:
cout << "\t\t\t\t";
break;
case 5:
cout << "\t\t\t\t\t";
break;
case 6:
cout << "\t\t\t\t\t\t";
}
mon = DaysInMonth(month, year);
for (j = 1; j <= mon; j++) //Printing the month's calendar
{
cout << " " << j << "\t";
c++;
if (!(c % 7))
cout << "\n";
}
}
int main()
{
 int x,y,z;
system("color 5f");
// Start_up();
char ch; char t = '\xCD';
do
{ 
system("cls"); // clrscr();
int i, date, year, month;
heading(t, 79);
cout << "\t\t\tCalendar of 700 years(1700-2400)\n";
heading(t, 79);
cout << "\nEnter 1 for knowing the day of a specific date\nEnter 2 to view the calendar of any given month\nEnter 3 to calculate your age ";
cin >> i;
if (i == 1) //OPTION 1
{
cout << "Enter date:(dd)";
cin >> date;
if (date>31 || date<1) //Condition for ambiguous date as input
{
cout << "\nPlease provide valid date.\t Press any key";
getch();
system("cls");
main();
}
month:
cout << "Enter month:(mm)";
cin >> month;
if (month>12 || month<1) //Condition for ambiguous month as input
{
cout << "\nPlease provide valid month.\t Press any key";
getch();
goto month;
}
year:
cout << "Enter year:(yyyy)";
cin >> year;
if (year>2400 || year<1700) //Condition for ambiguous month as input
{
cout << "\nPlease enter year within given range (1700 - 2400 ).\t Press any key";
getch();
goto year;
}
calender obj(date, month, year);
i = obj.DayNumber(--date, month, year);
cout << "\n" << ++date << "/" << month << "/" << year << " is ";
i=i%7;
obj.day(i); // for printing the day name
}
else if (i == 2) //OPTION 2
{
cout << "Enter month:(mm)";
cin >> month;
month2:
if (month>12 || month<1) //Condition for ambiguous month as input
{
cout << "\nPlease provide valid month.\t Press any key";
getch();
goto month2;
}
cout << "Enter year:(yyyy)";
cin >> year;
year2:
if (year>2400 || year<1700) //Condition for ambiguous month as input
{
cout << "\nPlease enter year within given range (1700 - 2400 ).\t Press any key";
getch();
goto year2;
}
calender obj;
obj.monthcal(month, year);
}
else if (i == 3)
{
cout<<"Enter your date of Birth:\n";
cout << "Day:(dd)";
cin >> date;
if (date>31 || date<1) //Condition for ambiguous date as input
{
cout << "\nPlease provide valid date.\t Press any key";
getch();
system("cls");
main();
}
month3:
cout << "Month:(mm)";
cin >> month;
if (month>12 || month<1) //Condition for ambiguous month as input
{
cout << "\nPlease provide valid month.\t Press any key";
getch();
goto month3;
}
year3:
cout << "Year:(yyyy)";
cin >> year;
if (year>2014 || year<1900) //Condition for ambiguous month as input
{
cout << "\nPlease enter year within given range (1900 - 2014 ).\t Press any key";
getch();
goto year3;
}
long int p;
calender dob(date, month, year);
p = dob.DayNumber(date, month, year);
// current date calculation
time_t t = time(0); // get time now
struct tm *now = localtime( &t );
date = now->tm_mday; //day
month = (now->tm_mon +1 );//month
year =(now->tm_year +1900 );//year
long int q;
calender cur(date, month, year);
q = cur.DayNumber(date, month, year);
int my_y = (q-p)/365;
int my_m = ((q-p)%365)/30;
int my_d = ((q-p)%365)%30;
cout<<"Your age is "<<my_y<<" years "<<my_m<<" months and "<<my_d<<" days.\n";
}
cout << "\nWould you like to try again (y/n)";
ch = _getch();
} 
while (ch == 'y' || ch == 'Y');
return 0;
}