JSFiddle - React, Tailwind, and code Playground

HTML

<div id="mytable1">10:20</div>
<div id="mytable2">13:00</div>

<button>Клик</button>
<div class="js-element"></div>

JavaScript

var p1 = convert($('#mytable1').text()+':00.00');
var p2 = convert($('#mytable2').text()+':00.00');

var diff;
(p1>p2) ? diff=p1-p2 : diff=p2-p1;
var hh = new Date(diff).getHours(), mm = new Date(diff).getMinutes(), ss = new Date(diff).getSeconds(), mss = new Date(diff).getMilliseconds();
(mm<10) ? mm='0'+mm:''; (ss<10) ? ss='0'+ss:''; (mss<100 && mss>10) ? mss='0'+mss:''; (mss<100 && mss<10) ? mss='00'+mss:'';
diff = hh-2+'-'+mm+'-'+ss+'-'+mss;

$('button').click(function() {
	$('.js-element').text(diff);
});

function convert(x){
	var one = x.split(':'),two = one[2].split('.');
	return new Date(0,0,0,one[0],one[1],two[0],two[1]);
}