Displaying Issue Involving Time - c++

Question

I am having trouble displaying "next day" in the correctly in my program. The assignment states, ".The user is prompted to enter the hour, min, second of the current processing time - currTime. Your program will compute the next processing time which is 30 mins after the current processing time. Your program will display the current processing timetime currTime and the next processing time 1 nextTime1 following processing time 2 nextTime2. If the next processing time goes to the next day then
you display “Next Day” next to the next processing time (see sample output).
The sample output shows:
Current Proc Time = 23:50:10 | Next Proc Time = 0:20:10 (Next Day) | Next Proc Time 2 = 0:50:10
My problem occurs during the bold line "Next Proc Time 2 = 0:50:10," in my code it displays (Next Day) in which it should not, only for the previous line, "Next Proc Time (Next Day" should it be displayed. So my question is what should I do to alter my code under the Void TimeType::Display() function to have it display "Next Day" when the day is equal to one correctly. Also, I apologize if my question is not too specific, I am just at a loss and do not know what to do to fix this issue.
#ifndef TIME_H
#define TIME_H
class TimeType { //class definition
private:
int sec;
int min;
int hr;
int day; // variable stores the information about the day, you need to track the transition to the next day
public:
TimeType();
void SetTime(int s, int m, int h, int d);
TimeType NextProcTime(void);
void Display();
};
#endif
#include <iostream>
#include <stdlib.h>
#include <stdio.h>
#include "timetype.h"
using namespace std;
TimeType::TimeType()
{
sec = 0;
min = 0;
hr = 0;
}
void TimeType::SetTime(int s, int m, int h, int d)
{
sec = s;
min = m;
hr = h;
day = d;
}
TimeType TimeType::NextProcTime(void)
{
long buf = 0;
int h, m, s, d;
buf = (day * 86400 + hr * 3600 + min * 60 + sec) + (30 * 60); //calculation time in seconds needed for the allocation of time to reflect additional minutes
d = buf / 86400; // recalculation time for days hours minutes seconds
h = (buf - 86400 * d) / 3600;
m = (buf - 86400 * d - 3600 * h) / 60;
s = (buf - 86400 * d - 3600 * h - 60 * m);
TimeType T; //creating a buffer TimeType object
T.SetTime(s, m, h, d); //full a buffer TimeType object
return T; //return buffer TimeType object
}
void TimeType::Display()
{
if (day == 1)
{
printf(" %02i:%02i:%02i (next day)\t", hr, min, sec);
}
else {
printf(" %02i:%02i:%02i \t", hr, min, sec);
}
};
int main(int argc, char *argv[])
{
int hr = 0, min = 0, sec = 0;
TimeType currTime, nextTime1, nextTime2;
char t;
do
{
system("cls");
while (1) {
cout << "Please enter the current processing hour." << endl;
cin >> hr;
if (hr >= 0 && hr < 24)
break;
cout << "Invalid Input, try again." << endl << endl;
}
cout << endl;
while (1)
{
cout << "Please enter the current processing minute." << endl;
cin >> min;
if (min >= 0 && min < 60)
break;
cout << "Invalid Input, try again." << endl << endl;
}
cout << endl;
while (1)
{
cout << "Please enter the current processing second." << endl;
cin >> sec;
if (sec >= 0 && sec < 60)
break;
cout << "Invalid Input, try again." << endl << endl;
}
cout << endl;
currTime.SetTime(sec, min, hr, 0);
nextTime1 = currTime.NextProcTime();
nextTime2 = nextTime1.NextProcTime();
cout << "Current Proc Time = ";
currTime.Display();
cout << endl;
cout << "Next Proc Time 1 = ";
nextTime1.Display();
cout << endl;
cout << "Next Proc Time 2 = ";
nextTime2.Display();
cout << endl;
cout << endl << "Do you have more data to enter? (y/n)" << endl;
cin >> t;
cout << endl;
} while (t == 'y'); // cycle for program multiple using
return 0;
}