JSFiddle - React, Tailwind, and code Playground

JavaScript

var date = new Date();;
          var array = GetAll(date);
          alert(array.join())
         

        function GetAll(date) {
           
            var month = date.getMonth();
            var lastDayOfMonth = new Date(date.getFullYear(), date.getMonth() + 1, 0);
            var lastDay = lastDayOfMonth.getDate();
            var array = [];  //dd/mm/yy
            for (var i = 1; i <= lastDay; i++) {
              
                var temp = new Date(date.getFullYear(), month, i);
                var day = temp.getDay();
                if (day == 4) // Thursday
                {
                   
                    var dd = temp.getDate();
                    var mm = temp.getMonth() + 1;
                    var mm0 = ('0' + mm.toString());
                    mm0 = mm0.length == 3 ? mm0.substring(1, 3) : mm0;

                    var dd0 = ('0' + dd.toString());
                    dd0 = dd0.length == 3 ? dd0.substring(1, 3) : dd0;
                  
                  
                    var yyyy = temp.getFullYear();
                        array.push(dd0  + '/' + mm0+ '/' + yyyy)
                }
            }
            return array;
        }