sub AddDate ( $ )
{
  my ( $datestr ) = @_;

  trim_whitespace ($datestr);

  my $DID;
  if ( !exists ( $hTempDates { $datestr }))
  {
    $DID = $nDate ++;
    
    $hDates { $DID }{ Date } = $datestr;
    $hTempDates { $datestr }{ ID } = $DID;
  }
  else
  {
    $DID = $hTempDates { $datestr }{ ID };
  }

  return $DID;
}