code: public static final Long getTimeBoxValue(TimeZone zone, Date date) {
  
          if (date == null) return null;
  
          // use a Calendar in the specified timezone to figure out the
          // time which is edited in a format independent of TimeZone.
          Calendar cal = GregorianCalendar.getInstance(zone);
          cal.setTime(date);
  
          // hh:mm (seconds and milliseconds are generally zero but we
          // include them as well)
          int hours = cal.get(Calendar.HOUR_OF_DAY);
          int minutes = cal.get(Calendar.MINUTE);
          int seconds = cal.get(Calendar.SECOND);
          int millis = cal.get(Calendar.MILLISECOND);
  
          return (((((hours * 60L) + minutes) * 60L) + seconds) * 1000L) + millis;
      }
docs: Returns an appropriate value for the UTCTimeBox for a specified
  {@link TimeZone} and {@link Date}.
  
  @param zone
  The {@link TimeZone} in which the Date will be
  rendered.
  
  @param date
  The Date which should be displayed in the UTCTimeBox
  
  @return the value for the UTCTimeBox or null if the supplied
  date is null