Matching algorithms for Semantic Web Services discovery focus on the functional aspects of the services, which are usually given by the function that transforms inputs into outputs. Current approaches do not take into attention the fact that some services may not be available around the clock and, more restrictively, may require exclusive access. In this paper we present an approach to allow the discovery of Web Services based on properties and temporal restrictions. We present a matching algorithm which leverages the work reported on the literature so as to consider availability matching. Throughout the paper, we illustrate our approach in the context of Web Services related to remote experiments, which may present rigid constraints in terms of both temporal restrictions and availability of resources.