getDayNames.js

function getDayNames(from, to) {
  var d = new Date(from),
    to = new Date(to),
    a = [],
    y = [
      "Sunday",
      "Monday",
      "Tuesday",
      "Wednesday",
      "Thursday",
      "Friday",
      "Saturday",
    ];
  while (d < to) {
    console.log(d.getDay());
    a.push(y[d.getDay()]);
    d.setDate(d.getDate() + 1);
  }
  if (d.getDay() === to.getDay()) a.push(y[d.getDay()]);
  console.log(a);
  a = a.filter((item, i, ar) => ar.indexOf(item) === i);
  return a;
}