getWeekDayOccurrences

const MS_IN_WEEK = 1000 * 3600 * 24 * 7;
const MS_IN_DAY = 1000 * 3600 * 24;

function setDay(date, day) {
  return new Date(date.getTime() + (day - date.getDay() * MS_IN_DAY));
}

function getWeekDayOccurrences(dateRange, dayId) {
  const [dayStart, dayEnd] = dateRange;

  const startDayId = dayStart.getDay();
  const endDayId = dayEnd.getDay();

  const firstDayAfterStartWeek = new Date(
    setDay(dayStart, 0).getTime() + MS_IN_DAY * 7
  );
  const lastDayBeforeEndWeek = new Date(
    setDay(dayEnd, 0).getTime()
  );


  const fullWeeks =
    Math.ceil((lastDayBeforeEndWeek - firstDayAfterStartWeek) / MS_IN_WEEK);

  let occurrences = fullWeeks>0?fullWeeks:0;

  if (fullWeeks>=0) {
    if (startDayId <= dayId) {
        occurrences += 1;
    }
    if (endDayId >= dayId) {
      occurrences += 1;
    }
  }else{
    if (startDayId <= dayId && endDayId >= dayId) {
        occurrences += 1;
      }
  }

  return occurrences;
}

console.log();
console.log();
console.log();
console.log();

console.log(
    getWeekDayOccurrences([new Date("2023/01/28"), new Date("2023/08/04")], 2),
  );