function Unix_timestamp(t)  
{  
var dt = new Date(t*1000);  
var hr = dt.getHours();  
var m = "0" + dt.getMinutes();  
var s = "0" + dt.getSeconds();  
return hr+ ':' + m.substr(-2) + ':' + s.substr(-2);    
}  
  
console.log(Unix_timestamp(1412743274));