code: public static String format(String pattern, Date date) {
  	synchronized (data) {
  	    Object obj = data.get(pattern);
  	    if (obj != null) {
  		return ((SimpleDateFormat) obj).format(date);
  	    } // print.ln(pattern);
  	    SimpleDateFormat sdf = new SimpleDateFormat(pattern);
  	    data.put(pattern, sdf);
  	    return sdf.format(date);
  	}
      }
docs: pool for formated dates
  
  @param pattern
  @param date
  @return date matching given values