Business appointments are necessary and the person with whom you are meeting will generally decide the time. Avoid scheduling meetings during July and August, the week before Easter, and the week between Christmas and New Year’s, as they are prime vacation times. It is expected to arrive on time to an appointment, as arriving late may create the impression of unreliability. Meetings are formal but first appointments are more social than business oriented, since Belgians prefer to do business with people they know. It is best not to remove your jacket during a meeting.
Read the complete commercial guide to Doing Business in Belgium