time stamp

revision:

the UNIX timestamp

The UNIX timestamp is an integer that represents the number of seconds elapsed since January 1, 1970.

You can fetch the current timestamp: 1/ by calling the now() method on Date object, 2/ by using the Javascript Date getTime() function, 3/ by using the JavaScript valueOf() method.

different methods

code: 
        <div>
            <p class="stamp" id="stamp"></p>
            <p class="stamp" id="stamp1"></p>
            <p class="stamp" id="stamp2"></p>
            <p class="stamp" id="stamp3"></p>
            <p class="stamp" id="stamp4"></p>
        </div>
        <style>
            .stamp{position: relative; }
        </style>
        <script>
            let ms = Date.now();
            console.log(ms);
            document.getElementById("stamp").innerHTML = "1 - Date.now() method : " + ms; 
            
            let milliseconds = new Date().valueOf();
            console.log(milliseconds);
            document.getElementById("stamp1").innerHTML = "2 - valueOf() method : " + milliseconds; 
           
            let millisecs = new Date().getTime();
            console.log(millisecs);
            document.getElementById("stamp2").innerHTML = " 3 - getTime() method : " + millisecs; 
          
            let millis = +new Date();
            console.log(millis);
            document.getElementById("stamp3").innerHTML = "4 - unary plus : " + millis;
            
            let mill = Number(new Date());
            console.log(mill);
            document.getElementById("stamp4").innerHTML = "5 - number constructor : " + mill;

            const unixTimestamp = Math.floor(Date.now());
            document.getElementById("stamp4a").innerHTML = "6 - Math.floor() method : " + unixTimestamp;
            console.log(unixTimestamp);

        </script>

convert time stamp to date

code:
        <div>
            <p class="datum" id="stamp5"></p>
            <p class="datum" id="stamp6"></p>
            <p class="datum" id="stamp7"></p>
            <p class="datum" id="stamp8"></p>
            <p class="datum" id="stamp9"></p>
            <p class="datum" id="stamp10"></p>
            <p class="datum" id="stamp11"></p>
            <p class="datum" id="stamp12"></p>
            <p class="datum" id="stamp13"></p>
            <p class="datum" id="stamp14"></p>
            <p class="datum" id="stamp15"></p>
            <p class="datum" id="stamp16"></p>
            <p class="datum" id="stamp17"></p>
        </div>
        <style>
            .datum{position: relative; width: 20vw; height: 2vw; padding: 1vw; 
                border: 0.2vw solid darkgrey; color: blue; background-color: lightgrey;}        
        </style>
        <script>
            var timestamp = 1655555253155
            var date = new Date(timestamp);
            document.getElementById("stamp5").innerHTML = "time stamp : " + date.getTime();
            document.getElementById("stamp6").innerHTML = "date : " + date;
            document.getElementById("stamp7").innerHTML = "date: " + date.getDate() + '/' + (date.getMonth()+1)
             + "/" + date.getFullYear() + " at " + date.getHours() + ":" + date.getMinutes();
            // convert to DateString()
            var ts= new Date(1655555630000);
            document.getElementById("stamp8").innerHTML = "toDateString(): " + ts.toDateString();
            // convert to ISOString()
            document.getElementById("stamp9").innerHTML = "toISOString(): " + ts.toISOString();
            //convert to GMTString()
            document.getElementById("stamp10").innerHTML = "toGMTString(): " + ts.toGMTString();
            // convert to JSON() 
            document.getElementById("stamp11").innerHTML = "toJSON(): " + ts.toJSON();
            // convert to LocaleDateString()
            document.getElementById("stamp12").innerHTML = "toLocaleDateString(): " + ts.toLocaleDateString();
            // convert to LocaleTimeString()
            document.getElementById("stamp13").innerHTML = "toLocaleTimeString(): " + ts.toLocaleTimeString();
            // convert to LocaleString()
            document.getElementById("stamp14").innerHTML = "toLocaleString(): " + ts.toLocaleString();
            // convert to String()
            document.getElementById("stamp15").innerHTML = "toString(): " + ts.toString();
            // convert to TimeString()
            document.getElementById("stamp16").innerHTML = "toTimeString(): " + ts.toTimeString();
            // convert to UTCString()
            document.getElementById("stamp17").innerHTML = "toUTCString(): " + ts.toUTCString();
        </script>