Vue Js Display date time of document when last modified/updated

<!DOCTYPE html>
<html>
<head>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app">
        <h3>Vue Js Display date time of document when last modified/updated</h3>
        <input v-model="myDataProperty" @input="updateLastModified()">
        <p>Last modified: {{ lastModified }}</p>
    </div>

input {
            padding: 12px 16px;
            font-size: 18px;
            border: none;
            border-radius: 6px;
            box-shadow: 0px 1px 3px rgba(0, 0, 0, 0.2);
            margin-bottom: 16px;
            width: 100%;
            background-color: #fff;
            transition: all 0.3s ease-in-out;
        }

input:focus {
            outline: none;
            box-shadow: 0px 1px 3px rgba(0, 0, 0, 0.4), 0px 0px 8px rgba(0, 0, 0, 0.1);
        }

p {
            font-size: 14px;
            color: #555;
            margin-top: 16px;
        }
    </style>

</body>

</html>