code: public static String formatDateRange(Context context, ReadablePartial start, ReadablePartial end, int flags) {
          return formatDateRange(context, toMillis(start), toMillis(end), flags);
      }
docs: Formats a date or a time range according to the local conventions.
  
  You should ensure that start/end are in the same timezone; formatDateRange()
  doesn't handle start/end in different timezones well.
  
  See {@link android.text.format.DateUtils#formatDateRange} for full docs.
  
  @param context the context is required only if the time is shown
  @param start the start time
  @param end the end time
  @param flags a bit mask of options
  @return a string containing the formatted date/time range