considering a module uses hooks to validate date is not a day of the week

OMG... :)
it sort works now... ignore the above code...
big thing I assumed was the value stored for date component was in a date format,
but it is not, it is in array like
Array ( [year] => 2012 [month] => 2 [day] => 16 )
which needs to implode before comparing with php date function.

cat *.module

function webform_validation_notday_webform_validation_validators() {
  return array(
    'not_day' => array(
      'name' => "Not Day of Week",
      'component_types' => array(
        'date',
      ),
      'custom_error' => TRUE,
      'custom_data' => array(
        'label' => t('Day of week not accepted for input, like the day of week you are closed'),
        'description' => t('Input a Day of week not accepted, use exact spelling used by php date for days, not a range, days
 are Sunday through Saturday, note first letter capitalized')
      ),
      'description' => t('Validates that date is not a specific day of the week for example you may be closed Monday.'),
    ),
  );
}

function webform_validation_notday_webform_validation_validate($validator_name, $items, $components, $rule) {
  if ($items) {
    switch ($validator_name) {
      case 'not_day':
        $notday = _webform_notday_check_data($rule['data']);
        foreach ($items as $key => $val) {
          // NOTE here is an example of how the date in $val is saved as an array,
          //         Array ( [year] => 2012 [month] => 2 [day] => 16 )
          // So we need to make a useable date from that like 2012/2/16 to see if it is the day of the week.
          $madeDate = implode("/",$val);
          $dw = date( "l", strtotime($madeDate));
          if ($dw == $notday) {
          $errors[$key] = _webform_validation_i18n_error_message($rule);
          }
        } //end foreach
        return $errors;
        break;
    } //end switch
  } //end if
} //end function

function _webform_notday_check_data($data) {
  $daysINweek = array("Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday");
  // if no value was specified, nothing to validate
  if ($data == '') {
    return $data;
  }
  // if value does not matches day of week return Notaday for now, later make an error thingy?
  if (in_array($data, $daysINweek)){
    return $data;
  } else {
    $data = "ERROR-AdminCompareDayBad";
    return $data;
  }
}

OKAY, while it would be great to not even allow input of unwanted dates or days..
at least here may be a way to not validate them.

sandbox for module that does NOT DAY:
http://drupal.org/sandbox/webengr/1429582

sandbox for module that does NOT DATE:
http://drupal.org/sandbox/webengr/1429636

I put two sandboxes up for validating against day of week and against a date.

I am changing from support request to feature request. If you think these features
should not be part of webform validation, then later I will consider changing the sandboxes to full projects.

-tia.

thanks...
I have not heard anything about it going into core..

If I do promote to full project, I would leave it "dev" for a long while till some more people pound on it.

I doubt the code is robust nor elegant... but it does seem to work for me. Let us know if you find
issues.. like timezones etc...

Likely the pattern matching could be better and use GNU formatting for day of week also....
.. wonder if it could have select radials and list the seven days... rather than having to use it upto 6 times to blackout
all but one day of week...

.... erase ....
---------- weird, it double posted ---------

Agreed a patch should be considered,

Like putting the bell on the cat, this mouse was 2 busy.... IF someone wants to make the patch - go ahead and let us know... else maybe in the future I will get around 2 it, but not for a couple months.