There are five categories of trains for domestic traffic in Belgium :
InterCity trains (IC) operate fast connections between the main cities
InterRegio trains (IR) ride between main cities with intermediate stops
Local trains (L) serve all station of the line
Peak trains (P) are additional trains that only run during peak hours
Tourist trains (T) only run during holidays and tourist season (summer)
IC and IR trains are cadenced, i.e. they have the same schedule schema all day long : if the first train leaves the station at 5.17 am, the following trains will leave each hour and 17 minutes. You can consult the IC/IR timetables on this website.
A search module is available on the official Belgian Railways website, and allows you the search a train schedule in the SNCB/NMBS database, including the connections with STIB/MIVB, TEC and DE LIJN vehicles :
(this link opens a page from the official website in a new window)
This page is maintained by David De Neef