code: @Override
      public <B extends Appendable> B format(Calendar calendar, final B buf) {
          // do not pass in calendar directly, this will cause TimeZone of FastDatePrinter to be ignored
          if(!calendar.getTimeZone().equals(mTimeZone)) {
              calendar = (Calendar)calendar.clone();
              calendar.setTimeZone(mTimeZone);
          }
          return applyRules(calendar, buf);
      }
docs: /* (non-Javadoc)
  @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Calendar, java.lang.Appendable)