Date Different in Month

//expected format date in = dd/mm/yyyy, return date rounded number in month
function dateDiffInMonth(startDate, endDate){
 // Convert to date type
 var aryTarikhMula = startDate.split('/');
 var tarikhMulaMDY = aryTarikhMula[1] + '/' + aryTarikhMula[0] + '/' + aryTarikhMula[2];
 var dtTarikhMula = new Date(tarikhMulaMDY);
 
 var aryTarikhTamat = endDate.split('/');
 var tarikhAkhirMDY = aryTarikhTamat[1] + '/' + aryTarikhTamat[0] + '/' + aryTarikhTamat[2];
 var dtTarikhAkhir = new Date(tarikhAkhirMDY);
 
 var diff = dtTarikhAkhir - dtTarikhMula;
 var diffInMonth = (diff/1000 / 60 / 60 / 24) / 30;
 diffInMonth = diffInMonth.toFixed(0);
 return diffInMonth;
}