Calculate days

[amackeyb]

I need to do a program that calculate the days from a date whatever
since 20XX to January 1st. 2000. How can I do that??
I have this, is it correct???

# include <iostream.h>
# include <conio.h>
void main()
{
int month, day, year, c_year, c_month, t_days;

cout<<"Give a date dd/mm/yy: "<<endl;
cout<<"Day: ";
cin>>day;
cout<<"Month: ";
cin>>month;
cout<<"Year: ";
cin>>year;
clrscr();

c_year=year*365;
c_month=(month-1)*30;
t_days=c_year+c_month+day;

cout<<"Days from"<<day<<"/"<<month<<"/"<<year<<" to January 1st. 2000:
"<<t_days;
}

[red floyd]

amackeyb wrote:

I need to do a program that calculate the days from a date whatever
since 20XX to January 1st. 2000. How can I do that??
I have this, is it correct???

No, it is not. See blow.

>
# include <iostream.h>

Non-standard header. Use <iostream>

# include <conio.h>

Non-standard header, don't know what it does.

using namespace std;

void main()

Undefined Behavior. Main *MUST* return int.
int main()

{
int month, day, year, c_year, c_month, t_days;

cout<<"Give a date dd/mm/yy: "<<endl;
cout<<"Day: ";
cin>>day;
cout<<"Month: ";
cin>>month;
cout<<"Year: ";
cin>>year;
clrscr();

you don't need to clear the screen. Kill this line (which
then also lets you remove that conio.h).

>
c_year=year*365;
c_month=(month-1)*30;

What about Jan, Feb, Mar, May, Jul, Aug, Oct, and Dec,
which don't have 30 days?

t_days=c_year+c_month+day;

cout<<"Days from"<<day<<"/"<<month<<"/"<<year<<" to January 1st. 2000:
"<<t_days;

cout << endl;

}

[Phlip]

red floyd wrote:

>void main()

Undefined Behavior. Main *MUST* return int.

I suspect it's ill-formed syntax. That occurs before any behavior.

--
Phlip
http://www.greencheese.us/ZeekLand <-- NOT a blog!!!

[Jim Langston]

"amackeyb" <am******@gmail.comwrote in message
news:11**********************@i3g2000cwc.googlegro ups.com...

>I need to do a program that calculate the days from a date whatever
since 20XX to January 1st. 2000. How can I do that??
I have this, is it correct???

# include <iostream.h>

#include <iostream>

# include <conio.h>

I wouldn't bother with this, unless you really wanted to.

void main()
{
int month, day, year, c_year, c_month, t_days;

cout<<"Give a date dd/mm/yy: "<<endl;
cout<<"Day: ";
cin>>day;
cout<<"Month: ";
cin>>month;
cout<<"Year: ";
cin>>year;
clrscr();

c_year=year*365;
c_month=(month-1)*30;

"Thirty days has September, April, June and November, all the rest have
thirty one, except for February which has 28, except on leap years has 31."

t_days=c_year+c_month+day;

cout<<"Days from"<<day<<"/"<<month<<"/"<<year<<" to January 1st. 2000:
"<<t_days;
}

[Sumit Rajan]

Jim Langston wrote:

>
"Thirty days has September, April, June and November, all the rest have
thirty one, except for February which has 28, except on leap years has 31."

Uh?!

[red floyd]

Phlip wrote:

red floyd wrote:

>>void main()

>Undefined Behavior. Main *MUST* return int.

I suspect it's ill-formed syntax. That occurs before any behavior.

Whoops! You're right!

[Jim Langston]

"Sumit Rajan" <su*********@gmail.comwrote in message
news:4p************@individual.net...

Jim Langston wrote:

>>
"Thirty days has September, April, June and November, all the rest have
thirty one, except for February which has 28, except on leap years has
31."

Uh?!

er, 29. Yeah. That's what I meant to say :D

[red floyd]

Jim Langston wrote:

"Sumit Rajan" <su*********@gmail.comwrote in message
news:4p************@individual.net...

>Jim Langston wrote:

>>"Thirty days has September, April, June and November, all the rest have
thirty one, except for February which has 28, except on leap years has
31."

Uh?!

er, 29. Yeah. That's what I meant to say :D

Easier one: "... all the rest have thirty one except for February which
is too complicated to discuss right now."

[Martin Steen]

amackeyb wrote:

I need to do a program that calculate the days from a date whatever
since 20XX to January 1st. 2000. How can I do that??
I have this, is it correct???

No, it's not that simple.

Visit http://www.javascript.martin-steen.de/astrodate.html
and view the page source. Then you see the "AstroDate"
formula in JavaScript (should be easy to understand for
C-programmers ;)

Best regards, Martin

P.S. litte translation help for german/english:
Jahr = year
Monat = month
Tag = day