JS | IIFE | Return UTC date as YYYYMMDD HH:MM:SS

(function yyyymmdd(dateIn) {
   var yyyy = dateIn.getUTCFullYear();
   var mm = dateIn.getUTCMonth()+1; // getMonth() is zero-based
   var dd  = dateIn.getUTCDate();
   var hh = dateIn.getUTCHours()
   var mn = dateIn.getUTCMinutes();
   var ss = dateIn.getUTCSeconds();
   return String(10000*yyyy + 100*mm + dd + " " + hh + ":" + mn + ":" + ss); // Leading zeros for mm and dd
})(new Date());