help with program

[phaldom]

how can i get this program to tell me the difference in the date entered to todays date in hours

#include <stdio.h>
#include <time.h>
#include <iostream>

using namespace std;
int main ()
{
time_t rawtime;
struct tm * timeinfo;
int year, month ,day;
char * weekday[] = { "Sunday", "Monday",
"Tuesday", "Wednesday",
"Thursday", "Friday", "Saturday"};

/* prompt user for date */
printf ("Enter year: "); scanf ("%d",&year);
printf ("Enter month: "); scanf ("%d",&month);
printf ("Enter day: "); scanf ("%d",&day);

/* get current timeinfo and modify it to the user's choice */
time ( &rawtime );
timeinfo = localtime ( &rawtime );
timeinfo->tm_year = year - 1900;
timeinfo->tm_mon = month - 1;
timeinfo->tm_mday = day;

/* call mktime: timeinfo->tm_wday will be set */
mktime ( timeinfo );

printf ("That day is a %s.\n", weekday[timeinfo->tm_wday]);
system ("pause");
return 0;
}

[kbw]

Have you looked at the fields in your timeinfo variable?

[phaldom]

seriouly im just beginning this stuff so im not sure what you mean by fields.. sorry but im guessing no

[kbw]

timeinfo is a record with a number of fields. You access them in:

timeinfo = localtime ( &rawtime );
timeinfo->tm_year = year - 1900;
timeinfo->tm_mon = month - 1;
timeinfo->tm_mday = day;

Have you looked at all of them? You'll find there's enough information to deduce the time difference.

[phaldom]

i havent and im not sure how to go about doing that...

[kbw]

This page shows what ought to be in time.h and shows the members of struct tm.
http://pubs.opengroup.org/onlinepubs/007908799/xsh/time.h.html