The work discusses nonmonotonicity in terms of trust management systems and presents model allowing for credential revocation in the Role-based Trust-management Framework. A freshness constraints have been adopted into RT Framework in order to overcome nonmonotonicity and turn it to be temporarily monotonic. The proposed model allows for freshness requirements specification on policy level and utilises freshness graph in order to perform propagation of freshness requirements along credential chains. Finally, an evaluation of the model against real-life scenario has been performed.