JSFiddle - React, Tailwind, and code Playground

HTML

<div>
<a id="start" >start<a>
<a id="stop">stop<a>
</div>
<br/>
senconds:
<div id="timer-s"></div>

minute:
<div id="timer-min"></div>

JavaScript

$(document).ready(function(){
var sencond = 1000;
var minute = 1000*60;
var handler = null;
var startTime = 0;
function startTimer(){     
    startTime = (new Date()).getTime();
    handler = setInterval(function(){showTime()},1000);
}
function showTime(){   
    var senconds = ((new Date()).getTime() - startTime)/sencond;
    senconds = senconds.toFixed(2);
    $('#timer-s').text(senconds+'s');
     var minutes = ((new Date()).getTime() - startTime)/minute;
    minutes = minutes.toFixed(2);
    $('#timer-min').text(minutes+'min');
}
function stopTimer(){
    clearInterval(handler);
}
$('#start').click(startTimer);
$('#stop').click(stopTimer);

});