A timetable can be produced dynamically, on request, for a particular journey on a particular day around a particular time (see journey planner, below), or in a timetable that gives an overview of all services in a particular category and is valid for a specified period. The latter could take the form of a book, leaflet, billboard, or a (set of) computer file(s), and makes it much easier to find out, for example, whether a transport service at a particular time is offered every day at that time, and if not, on which days; with a journey planner one may have to check every day of the year separately for this.
