How to pause and restart the Qtimer on QT

I have a Ubuntu , and i'am working with IDE QT on C++ . I will to pause and resume the Qtimer , for exampe :

void Ordonnancer_les_taches::on_pushButton_clicked()
{

    connect(&dataTimer, SIGNAL(timeout()), this, SLOT(l_odonnancement()));
    dataTimer.start(5000);
}

How to Pause and how Restart ? give me an exmple