Online calendars

There are many online channels where you can announce your activity, such as the UiTdatabank. See here how you can enter an event in the UiTdatabank. The activities from the UiTdatabank are fed into more than 500 calendars, including UiTinvlaanderen. Other online calendars include www.wattedoen.be, www.waarnaartoe.be, etc.

Your own city probably also has an activities calendar. Perhaps your event could be included there?