// to specify date in current and next month dynamically
var year = new Date().getFullYear();
var month = new Date().getMonth();
var month2 = new Date().getMonth() +1;
var day = new Date().getDate();

var startDate = new Date(`${year}-${month < 10 ? '0' : ''}${ month }-26`); //YYYY-MM-DD
var endDate = new Date(`${year}-${month2 < 10 ? '0' : ''}${ month2 }-25`); //YYYY-MM-DD

// or to specify range in specific range
var startDate = new Date("2019-08-26"); //YYYY-MM-DD
var endDate = new Date("2019-08-26"); //YYYY-MM-DD

function formatDate(date) {
  const year = date.getFullYear();
  /* getMonth returns dates from 0, so add one */
  const month = date.getMonth() + 1;
  const day = date.getDate();

  return `${year}-${month < 10 ? '0' : ''}${ month }-${ day < 10 ? '0' : '' }${day}`
}

var getDateArray = function(start, end) {
    var arr = new Array();
    var dt = new Date(start);
    while (dt <= end) {
        arr.push(new Date(dt));
        dt.setDate(dt.getDate() + 1);
    }
    return arr;
}

var dateArr = getDateArray(startDate, endDate);




function shuffle(arra1) {
    var ctr = arra1.length, temp, index;

// While there are elements in the array
    while (ctr > 0) {
// Pick a random index
        index = Math.floor(Math.random() * ctr);
// Decrease ctr by 1
        ctr--;
// And swap the last element with it
        temp = arra1[ctr];
        arra1[ctr] = arra1[index];
        arra1[index] = temp;
    }
    return arra1.map(formatDate);;
}

console.log(shuffle(dateArr));