Every full and half-hour, between trips on demand
1. Jan 2017 - 28. Feb 2017
9.00 - 16.00 
1. March 2017 - 17. April 2017
8.30 - 17.00 
18. April 2017 - 28. April 2017
closed because of maintenance 
29. April 2017 - 30. Juni 2017
8.30 - 17.00 
1. July 2017 - 30. September 2017
8.30 - 17.30
1. October 2017 - 22. October 2017
8.30 - 17.00 

23. October 2017 - 15. December 2017 

Change autumn revision short term via homepage

16. December 2017 - 28. February 2018
9.00 - 16.00
Subject to change.