1. A method for operating a system to provide temporal context for recommending items for consumption by a user device, comprising: maintaining on a storage medium a record of items consumed by the user device or a group of devices within a reference period, together with the time of consumption of each item, and a content descriptor associated with each item; identifying temporal consumption periods within the reference period, each temporal consumption period spanning the consumption of one or more items with similar content descriptors, and associating each temporal consumption period with its respective content descriptor; creating an aggregated list of temporal consumption periods recorded over a plurality of reference periods; identifying clusters of similar temporal consumption periods in the aggregated list; identifying recurring temporal patterns for user device behaviour in each cluster; constructing a profile for each user device based on the clusters and the recurring temporal patterns for each cluster; and using the profile to provide the temporal context at the user device.