A system and method for expanding recurring calendar events such that the retrieval of recurring calendar appointments is expedited. A recurring appointment is saved as a data structure including a recurrence pattern. When a recurring appointment is saved by a client that has sufficient processing and memory resources to perform the computations necessary to expand recurring appointments (i.e., a thick client), a background thread is notified. The background thread increases its priority to normal when idle processing capacity is available and calls a routine requesting calendar information for a defined time period. The routine causes the expansion of the data structure into the individual instances of the recurring appointment for a defined time period, and the individual instances are saved for later retrieval. A later query from a client without sufficient processing and memory resources to perform the calculations necessary to expand recurring appointments (i.e., a thin client), therefore, does not require that the expansion computations be performed contemporaneously.