Present Simple (I do) with a future meaning.

We can use the Present Simple when we talk about timetables, programmes, etc.  (For example, for public transport, cinemas etc)

• The train leaves Mumbai at 9.30 a.m and arrives at Bilaspur within 16 hours.
• What time does the film begin?
• The film begins at 6.00 p.m.
• We have a bus now going to Thiruvanathapuram.  It leaves at 9 a.m.