If you're using it within an insert or update command, there's little point assigning it to a variable, instead do something like this:
PDO
$pdo = $connDB->prepare("INSERT INTO tbl_Name(Something,SomethingElse,SomeDate) VALUES (?,?,NOW())");
$pdo->execute(array($intSomething,$strSomethingElse));
or
mysqli
$stmt = $mysqli->prepare("INSERT INTO tbl_Name(Something,SomethingElse,SomeDate) VALUES (?,?,NOW())");
$stmt->bind_param('is', $intSomething, $strSomethingElse);
$stmt->execute();
$stmt->close();
To dispalay a timestamp as DD/MM/YYYY
$datSomeDate = strftime("%d/%m/%Y", strtotime($datSomeDate ));