JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://code.jquery.com/ui/1.9.0/themes/base/jquery-ui.css">
<div>Date: <input type="text" name="date" id="useDatePicker"/></div>
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<div> Result: <input type="text" name="result" id="result" /></div>

JavaScript

$('#useDatePicker').datepicker({
    onSelect:function(date){
        
        var today=new Date();
            
        var result=DateDiff(today,new Date(date));
        
       $('#result').val(result); 
        
        
    }        
    
    
});


function DateDiff(date1,date2) {
    var diff=date1 - date2;
    var num_years = diff/31536000000;
var num_months = (diff% 31536000000)/2628000000;
var num_days = ((diff% 31536000000) % 2628000000)/86400000;
       
        return Math.floor(num_years)+"years "+Math.floor(num_months)+"months "+Math.floor(num_days)+"days";
}