Code

time.h

class time{
private:
    int hours;
    int minutes;
    int second;
public:
    time();
    time(int h, int m, int s);
    void normalize();
    void reset(int h, int m, int s);
    void advance(int h, int m, int s);
    void print();
};

time.cpp

#include <iostream>
#include "time.h"
using namespace std;

time::time()
{
    hours = 0;
    minutes = 0;
    second = 0;
}

time::time(int h, int m, int s)
{
    hours = h;
    minutes = m;
    second = s;
}

void time::normalize()
{
    minutes += second / 60;
    second %= 60;
    hours += minutes / 60;
    minutes %= 60;
    hours %= 24;
}

void time::reset(int h, int m, int s)
{
    hours = h;
    minutes = m;
    second = s;
    normalize();
}

void time::advance(int h, int m, int s)
{
    hours += h;
    minutes += m;
    second += s;
    normalize();
}

void time::print()
{
    cout << hours << ':' << minutes << ':' << second << endl;
}

main.cpp

#include <iostream>
#include "time.h"
using namespace std;

int main()
{
    int h, m, s;
    time t1;

    t1.print();

    cout << "Enter The Hours : ";
    cin >> h;

    cout << "Enter The Minutes : ";
    cin >> m;

    cout << "Enter The Seconds : ";
    cin >> s;

    t1.reset(h, m, s);

    t1.print();

    t1.advance(70, 100, 400);

    cout << "After the increase :\\n";
    t1.print();
}