In general, an international ticket is issued for each single journey. The date and the period of validity are shown on the ticket. The period of validity depends on, among other things, the type of train, the destination, the distance, the fare, etc. Here are some examples:
Eurostar and TGV:
Each ticket is valid on a specific date and time.
Towards Belgium (Intercity and local trains):
Each ticket is valid for 1 day.
(Super)Saver/Early Bird tickets for Eurocity Direct / EuroCity / Intercity Brussels are only valid for the train with the chosen time of departure as indicated on your ticket and in the booking confirmation.
Towards Germany and beyond:
Tickets are valid for 1 day for distances of up to 100 km.
Tickets are valid for 2 days for distances greater than 100 km.
The period of validity of the part of the ticket in the Netherlands is always 1 day.
A single-use chipkaart (available from NS ticket machines or at NS Tickets & Service Desks) is valid for 4 days.
The period of validity of the part of the ticket in the Netherlands is always 1 day.
A ticket for a specific train, for example the Sparpreis Europa fare, is valid on the date and train you chose when you bought it.
This applies for all ICE, IC and EC trains during your journey. For all other trains (for example the connecting journey in the Netherlands, RE and S trains) you may travel within your ticket’s period of validity.