You don't even need a pass to plan.

In addition, planning is best not done in the rail planner app. It's incomplete, often out of date and generally unreliable. National or the operators’ own planners are much more reliable; for international journeys, bahn.de or the DB Navigator app is a good choice.

Timetables from 15 December are largely not available yet. Most will become available sometime in October. The exact date depends on the operator.