A method and system for aggregating and reporting data from a plurality of data sources in a contact center is provided. The method includes: maintaining by a computer device the data for a sliding interval including a plurality of panes, the data including an ongoing component for ongoing events and a completed component for completed events; updating by the computer device the data for the sliding interval based on updates for the sliding interval received from one or more of the data sources; and reporting by the computer device an aggregation of the ongoing and completed components of the data sources for the sliding interval to a client in accordance with an expiring of one of the panes. The system includes a processor and a non-transitory physical medium. The medium has instructions stored thereon that, when executed by the processor, causes the processor to execute the method.