JSFiddle - React, Tailwind, and code Playground

HTML

<div id="log"></div>

JavaScript

var tests = [
    "bla bla",      // false
    "14/09/2011",   //         true
    "09/14/2011",   // false
    "14/9/2011",    // false
    "1/09/2011",    // false
    "14/09/11",     // false
    "14.09.2011",   // false
    "14/00/2011",   // false
    "29/02/2011",   // false
    "14/09/9999",   //         true
];

function parseDate(str){
    var t = str.match(/^(\d{2})\/(\d{2})\/(\d{4})$/);
    if(t!==null){
      var d=+t[1], m=+t[2], y=+t[3];
      var date = new Date(y,m-1,d);
      if(date.getFullYear()===y && date.getMonth()===m-1){
        return date;   
      }
    }
    return null;
}

$.each(tests, function(i,e){
    $('#log').append('<p>' + e + ' --> ' + parseDate(e) + '</p>');
});