A day pass (dagkaart) is a great money saving option if you need to travel by bus several times on a single day. You can buy them from a bus driver for €6. This grants you unlimited travel after 09:00 with the Arriva buses for one day. Remember to store your ticket securely and show it to the driver whenever you enter a bus. The Arriva website provides details about the day pass (all in Dutch).
For €12.50 you can buy a dagkaart which allows you to travel on Arriva trains as well as buses in Limburg. This ticket is valid on the route Maastricht Randwyck – Kerkrade Centrum between 09:00 and 16:00. You can buy the tickets from the Arriva ticket machines in the station. If you need to travel by bus or train before 09:00 A.M. you will have to buy an additional ticket (‘PLUSkaart’) for €2,50. Have look at the terms and conditions of this offer (only in Dutch).
The NS only offers a day pass if you have an OV-chip card and it will cost you €51,40. Read the most up-to-date information about prices and conditions on the NS website.
Arriva offers another type of dagkaart which is not valid for all of the Netherlands but for the whole Euregio Maas-Rhine. For 18.50€ you can use a variety of trains and buses in the provinces of Limburg (Netherlands) and Liege (Belgium), as well as in the Regio Aachen (Germany). The ticket is valid for the whole day on which it is stamped; it’s valid for a single person on regular calendar days and on holidays it is even valid for up to 2 adults and 3 children. For more detailed information go here (all in Dutch).