Date.shortMonths = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];  
  
function short_months(dt)  
   {   
     return Date.shortMonths[dt.getMonth()];   
   }  
  
dt = new Date();   
console.log(short_months(dt));   
  
dt = new Date(2015, 10, 1);   
console.log(short_months(dt));