def end_of(self, event_id, import_options=True):
        """
        Set Date-Picker as the end-date of a date-range.

        Args:
            - event_id (string): User-defined unique id for linking two fields
            - import_options (bool): inherit options from start-date input,
              default: TRUE
        """
        event_id = str(event_id)
        if event_id in DatePickerDictionary.items:
            linked_picker = DatePickerDictionary.items[event_id]
            self.config['linked_to'] = linked_picker.config['id']
            if import_options:
                backup_moment_format = self.config['options']['format']
                self.config['options'].update(linked_picker.config['options'])
                self.config['options'].update(self.options_param)
                if self.format_param or 'format' in self.options_param:
                    self.config['options']['format'] = backup_moment_format
                else:
                    self.format = linked_picker.format
            # Setting useCurrent is necessary, see following issue
            # https://github.com/Eonasdan/bootstrap-datetimepicker/issues/1075
            self.config['options']['useCurrent'] = False
            self._link_to(linked_picker)
        else:
            raise KeyError(
                'start-date not specified for event_id "%s"' % event_id)
        return self
Set Date-Picker as the end-date of a date-range.

        Args:
            - event_id (string): User-defined unique id for linking two fields
            - import_options (bool): inherit options from start-date input,
              default: TRUE