when writing a php function to odbc datasource the source code fails

While your issue involves read-only permissions on the data source file, consider two best practices going forward:

• Parameterization to facilitate code security especially with $POST variables as well as readability and maintainability without need of messy variable concatenation or quote punctuation. Parameters are supported in the odbc library using odbc_prepare.

• Error handling using try/catch for more informative errors or exceptions per this answer.

Below uses MS Access’s CDate() and avoid need of enclosing # and converts numeric types of parameters with PHP’s floatval. Adjust untested code as needed.

// ENSURE ERRORS RAISE AS EXCEPTIONS
set_error_handler(
    function($errno, $errstr, $errfile, $errline ) { 
        throw new ErrorException($errstr, $errno, 0, $errfile, $errline);
    }
);

// PREPARED STATEMENT WITH ? PLACEHOLDERS
$sql = "INSERT INTO Zeitkarten
          (BeginnTätigkeit, EndeTätigkeit, Mitarbeiter, Projekt, ArbeitscodeNr,
           datum, [Pause], AnzahlUeber, FZhin, FZrueck, Anmerkung) 
        VALUES (CDate(?), CDate(?), ?, ?, ?, CDate(?), ?, ?, ?, ?, ?)";

try { 
    // BIND PARAMS AND EXECUTE
    $stmt = odbc_prepare($con, $sql);
    $result = odbc_execute(
         $stmt, 
         array( 
             $_POST['kommen'],
             $_POST['gehen'], 
             $benutzer, 
             $_POST['projekt'], 
             $_POST['adt'], 
             $_POST['heute'],
             floatval(str_replace(",", ".", $_POST['pause'])),
             floatval(str_replace(",", ".", $_POST['ama'])),
             floatval(str_replace(",", ".", $_POST['fzhin'])),
             floatval(str_replace(",", ".", $_POST['fzrueck'])),
             $_POST['anmerkung']
         )
    ); 

    echo $result; 
} catch (Exception $e) { 
    // ECHO EXCEPTION MESSAGE
    echo $e->getMessage(); 
}