Digital Clock starting from user set time in C++

Last Updated : 25 Mar, 2021

In this article, we will discuss the Digital Clock in C++ Language. It is an application that allows for a personal clock that starts at a custom set time and shows the time from that point onwards. This article describes how to make such a clock in a 24-hour format with HH:MM:SS slots and start the time from where one would want it to be, and then it moves forward from there.

Features: It is a Simple Digital clock developed using basic C++ concepts that shows hour, minute, and second.

Approach: The requirements for this program are just the basic concepts of the data types, variables, manipulators, Control statements, Conditional statements, etc. Below are the steps:

Create a screen that will show "Current time" of your location which will be implemented using simple output methods used in C++ i.e., cout, and a manipulator "setw()".
In the fore mentioned screen, implement the HH column, MM column, SS column, that will contain the time.
Implement colors using System("color 4A"), the color will be in hexadecimal format and the console can be used to implement them using double-digit hex codes (0 to F) which will, in turn, change the text color in the console of the output.
In the last screen, a digital clock can be seen finally implemented and running from the inputted time.

Functions Used:

System("cls"): It is used to clear the Console or the Screen. It can be avoided if anyone wants to see whatever is appearing on the screen.
setw(): This function is used to leave the space of particular characters that you can write in the parenthesis. It is declared in <iomanip> header file. Here setw(70) is used.
System("color 4A"): This function is used to make background RED and text as LIGHT GREEN.
Sleep(): sleep is a function that is declared in <windows.h> header file. It actually suspends the execution of the program temporarily for a period of time in milliseconds.

Below is the implementation of the above approach:

C++

// C++ program to illustrate the digital
// clock starting from the entered time

#include <iomanip>
#include <iostream>
#include <stdlib.h>
#include <windows.h>
using namespace std;

// Driver Code
int main()
{
    system("color 4A");

    // Background color and Foreground
    int hour, min, sec;
    cout << setw(70)
         << "*Enter Current time*\n";

    // Use of manipulator for taking
    // input from the user
    cout << "HH- ";
    cin >> hour;
    cout << "MM- ";
    cin >> min;
    cout << "SS- ";
    cin >> sec;

    // Background color and the
    // Foreground for 2nd screen
    system("color 4A");

    // Cases for the Wrong Time Input
    if (hour > 23) {
        cout << "Wrong Time input";
    }
    else if (min > 60) {
        cout << "Wrong Time Input";
    }
    else if (sec > 60) {
        cout << "Wrong Time Input";
    }

    // Otherwise
    else {
        while (1)

        // Run Block infinitely
        {
            system("cls");

            // Clear the console

            // Code for Showing Time
            for (hour; hour < 24; hour++) {

                for (min; min < 60; min++) {

                    for (sec; sec < 60; sec++) {
                        system("cls");

                        cout << "\n\n\n\n~~~~~~~~~"
                                "~~~~~~~~~~~~~~~~~~~~~"
                                "~~~~~~~~~~~~~~~~~~"
                                "Current Time = "
                             << hour << ":" << min << ":"
                             << sec
                             << "Hrs~~~~~~~~~~~~~~~~~~"
                                "~~~~~~~~~~~~~~~~~~~~~"
                                "~~~~~~~~~";

                        // HH:MM:SS columns in output

                        Sleep(1000);

                        // Pause for 1 sec
                    }
                    sec = 0;
                }
                min = 0;
            }
        }
    }
}