<html>

    <head>

        <meta charset="utf-8">

        <meta http-equiv="X-UA-Compatible" content="IE=edge">

        <meta name="viewport" content="width=device-width,initial-scale=1">



        <title>Time Calculator</title>

        <meta name="description" content="Calculate time by adding or subtracting hours, minutes, or seconds.">

        <meta name="keywords" content="time calculator, calculate time, add time, subtract time">



        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>

        <link href="https://stackpath.bootstrapcdn.com/bootstrap/5.0.2/css/bootstrap.min.css" rel="stylesheet"

                integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC" crossorigin="anonymous">

        <link href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet">

        <link href="https://fonts.googleapis.com/css?family=Open+Sans" rel="stylesheet">



        <script type="text/javascript">

            try {

                document.addEventListener("DOMContentLoaded", function() {

                    // Get the input fields and the result container

                    const timeInput = document.getElementById("time-input");

                    const hoursInput = document.getElementById("hours-input");

                    const minutesInput = document.getElementById("minutes-input");

                    const secondsInput = document.getElementById("seconds-input");

                    const resultContainer = document.getElementById("result-container");



                    // Add event listeners to the input fields

                    timeInput.addEventListener("input", calculateTime);

                    hoursInput.addEventListener("input", calculateTime);

                    minutesInput.addEventListener("input", calculateTime);

                    secondsInput.addEventListener("input", calculateTime);



                    // Calculate the time based on the input values

                    function calculateTime() {

                        const time = timeInput.value;

                        const hours = parseInt(hoursInput.value) || 0;

                        const minutes = parseInt(minutesInput.value) || 0;

                        const seconds = parseInt(secondsInput.value) || 0;



                        // Parse the time input

                        const parsedTime = time ? new Date(`1970-01-01T${time}`).getTime() : 0;



                        // Add or subtract the input values from the parsed time

                        const calculatedTime = parsedTime + hours * 3600000 + minutes * 60000 + seconds * 1000;



                        // Format the calculated time

                        const formattedTime = new Date(calculatedTime).toISOString().substr(11, 8);



                        // Display the result

                        resultContainer.textContent = formattedTime;

                    }

                });



            } catch (error) {

                throw error;

            }

        </script>

        

        <style>

            body {

                font-family: 'Open Sans', sans-serif;

                background-color: #f1f1f1;

            }

            

            .container {

                max-width: 600px;

                margin: 0 auto;

                padding: 40px;

                background-color: #fff;

                box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);

                border-radius: 5px;

            }

            

            h1 {

                text-align: center;

                margin-bottom: 20px;

                color: #333;

            }

            

            .form-group {

                margin-bottom: 20px;

            }

            

            label {

                font-weight: bold;

                color: #777;

            }

            

            input[type="text"] {

                width: 100%;

                padding: 10px;

                border: 1px solid #ccc;

                border-radius: 3px;

                font-size: 16px;

            }

            

            .result {

                text-align: center;

                font-size: 24px;

                color: #333;

            }

        </style>

    </head>

    <body>

        <div id="main-container" class="container">

            <h1>Time Calculator</h1>

            

            <div class="form-group">

                <label for="time-input">Time:</label>

                <input type="text" id="time-input" placeholder="hh:mm:ss">

            </div>

            

            <div class="form-group">

                <label for="hours-input">Hours:</label>

                <input type="text" id="hours-input" placeholder="0">

            </div>

            

            <div class="form-group">

                <label for="minutes-input">Minutes:</label>

                <input type="text" id="minutes-input" placeholder="0">

            </div>

            

            <div class="form-group">

                <label for="seconds-input">Seconds:</label>

                <input type="text" id="seconds-input" placeholder="0">

            </div>

            

            <div id="result-container" class="result"></div>

        </div>

    </body>

</html>