The line of code that you will need to edit is on line 256, here is the line:
echo "WAJA[".$n."][".$m."][1] = "."'".WA_DD_Replace($row_child["surgery_date"])."'".";\n";
You will need to apply the date formatting function around the recordset value on this line:
date("your format string", $row_child["surgery_date"])