Monitoring coordinated groups of devices working collectively toward global objectives is increasingly crucial, particularly in high-stakes scenarios such as emergency response and disaster recovery. A promising strategy in this domain involves specifying desired global behaviours using spatial or temporal logics, which can then be systematically translated into distributed monitors that operate at runtime. Frameworks like Aggregate Computing (AC) provide a principled foundation for such translations, enabling decentralized systems to reason about and react to complex temporal patterns. However, the expressiveness of temporal logics currently supported in AC often falls short of capturing the nuanced and time-sensitive properties required in many real-world applications, limiting the scope and effectiveness of existing monitoring approaches.

In this paper, we introduce bounded past-CTL, an extension of past Computational Tree Logic (past-CTL) that incorporates bounded-time modalities, enabling the specification of temporal properties constrained to finite historical windows. This logic enhances the expressiveness and practical applicability of past-CTL in runtime verification tasks, particularly in time-sensitive systems. We also present an automated approach for synthesizing runtime monitors for bounded past-CTL specifications directly in the eXchange Calculus (XC), a high-level aggregate computing language designed for resilient distributed systems. Our method leverages the compositional semantics of XC to generate decentralized and efficient monitors capable of capturing bounded temporal behaviours across dynamic network topologies. We demonstrate the effectiveness of our approach through illustrative examples, highlighting the scalability and expressiveness of the synthesized monitors in realistic scenarios.