code: public final void setTimeZone(final TimeZone timezone) {
  		this.timezone = timezone;
  		if (timezone != null) {
  			getFormat().setTimeZone(timezone);
  		} else {
  			resetTimeZone();
  		}
  		time = new Time(time, getFormat().getTimeZone(), false);
  	}
docs: Sets the timezone associated with this date-time instance. If the
  specified timezone is null, it will reset to the default timezone. If the
  date-time instance is utc, it will turn into either a floating (no
  timezone) date-time, or a date-time with a timezone.
  
  @param timezone
  a timezone to apply to the instance