The monthly pass is valid for one month from the first day of validity until midnight (24:00 CET) on the last day of validity. For example from 12 May until 11 June (midnight). Or from 18 December until 17 January (midnight) of the next year.
During this period you can make as many journeys as you like within the purchased zones. The monthly pass is the second-cheapest network ticket and ideal for all regular customers who wish to retain their flexibility