function isDate($spos)
    {
        //$xfindex = GetInt2d(, 4);
        $xfindex = ord($this->data[$spos+4]) | ord($this->data[$spos+5]) << 8;
        //echo 'check is date '.$xfindex.' '.$this->formatRecords['xfrecords'][$xfindex]['type']."\n";
        //var_dump($this->formatRecords['xfrecords'][$xfindex]);
        if ($this->formatRecords['xfrecords'][$xfindex]['type'] == 'date') {
            $this->curformat = $this->formatRecords['xfrecords'][$xfindex]['format'];
            $this->rectype = 'date';
            return true;
        } else {
            if ($this->formatRecords['xfrecords'][$xfindex]['type'] == 'number') {
                $this->curformat = $this->formatRecords['xfrecords'][$xfindex]['format'];
                $this->rectype = 'number';
                if (($xfindex == 0x9) || ($xfindex == 0xa)){
                    $this->multiplier = 100;
                }
            }else{
                $this->curformat = $this->_defaultFormat;
                $this->rectype = 'unknown';
            }
            return false;
        }
    }