An aperitif is generally served before dinner in order to stimulate the appetite. A nice aperitif is Dubonnet, which is a slightly spiced red wine. Generally heavier drinks are not considered an aperitif.
An aperatif is a before dinner drink. An aperatif is good for the appetite. A digestive is an after dinner drink. A digestive is good for the digestion.
An apertif is a liquer either served by itself or mixed with ice and a mixer such as club soda or orange juice to prepare the palate for food, so the correct time is before dinner.
