Modelling the semantics of calendar expressions as extended regular expressions

This paper proposes modelling the semantics of natural-language calendar expressions as extended regular expressions (XREs). The approach covers expressions ranging from plain dates and times of the day to more complex ones, such as the second Tuesday following Easter. Expressions denoting disconnected periods of time are also covered. The paper presents an underlying string-based temporal model, sample calendar expressions with their XRE representations, and possible applications in temporal reasoning and natural-language generation.