transaction.date in pdf

Hi!
I need to replace getTodaysDate with transaction.date
$pdf->Cell(0,6,$_LANG["invoicesdatecreated"].': '.getTodaysDate(1).'',0,1,'L','1'); -> on this line
$pdf->Cell(0,6,$_LANG["datum_placila"].': '.getTodaysDate(1).'',0,1,'L','1');
any solutions?
regards