public function setWorkingDays(array $days, $format = null)
    {
        $this->workingDays = $days;
        if ($format) {
            $this->formatWorkingDays = $format;
        }
        return $this;
    }
public function setWorkingDays(array $days, $format = null)
    {
        $this->workingDays = $days;
        if ($format) {
            $this->formatWorkingDays = $format;
        }
        return $this;
    }
public function setWorkingDays ( array $ days , $ format = null ) { $ this -> workingDays = $ days ; if ( $ format ) { $ this -> formatWorkingDays = $ format ; } return $ this ; }
Set working days as exclusion.

@param array $days
@param null $format
@return $this
Set working days as exclusion .