The Cascadia system provides RFID-based pervasive computing applications with an infrastructure for specifying, extracting and managing meaningful high-level events from raw RFID data. Cascadia allows users to specify events of interest using a graphical interface with an intuitive visual language. Cascadia also effectively extracts these events from data in spite of the unreliability of RFID technology and the inherent ambiguity in event extraction. We demonstrate Cascadia's technique through a digital diary application in the form of a calendar. Cascadia automatically populates the calendar with meaningful events for the user. We use data collected in a building-wide RFID deployment. Categories and Subject Descriptors H.2.4 [Information Systems]: Database Management Systems ; H.5.2 [Information Systems]: Information Interfaces and Presentation User Interfaces General Terms algorithms, design, experimental Keywords probabilistic event extraction, user interfaces, RFID