function addDays(date, days,seperator='-') {

  let oDate = new Date(date).valueOf();

  let nDate = oDate + days * 24 * 3600 * 1000;

  nDate = new Date(nDate);

  let y = nDate.getFullYear().toString().padStart(2, 0);

  let m = (nDate.getMonth() + 1).toString().padStart(2, 0);

  let d = nDate.getDate().toString().padStart(2, 0);

  return `${y}${seperator}${m}${seperator}${d}`

}