Question

I have a project that needs me to accept an input for when (during the same day, I assume) an assignment is due. I was trying to follow some code from a similar question but it’s giving me an error, which I assume has to do with time_t and int values. Here’s my code:

#include <iostream>
#include <ctime>
using namespace std;

int main() {
 int hour_input,min_input;

 cout << "What hour is your assignment due?\n";
 cin >> hour_input;
 cout << "What minute is your assignmnet due?\n";
 cin >> min_input;

 struct tm* tm;
 time_t ts = time(NULL);
 long int delta;
 tm->tm_hour = hour_input;
 tm->tm_min = min_input;

 delta = mktime(tm) - ts;
 delta += 24*60*60;
 cout << "There are "<< delta << " minutes until your assignment is due!\n";

 return 0;
}

What I’m looking for is some guidance on how to use the functions within the <ctime> header properly, thanks for your help!

Answer 1

double deltaMinutes = difftime(later,earlier) / 60.0;

I’d initialize each time struct to the current date. Note, that 1970 is designated by 70 in member tm::tm_year.

http://www.cplusplus.com/reference/clibrary/ctime/difftime/