Systems and methods can use a testing framework for testing an event processing system. The testing framework operates to send one or more input events in an event stream to an event processing system, wherein each said input event is associated with a timestamp. Also, the testing framework can receive one or more actual output events from the event processing system, wherein each said actual output event is associated with a timestamp. Furthermore, the testing framework can compare said one or more actual output events in an event window with one or more expected output events for the event window.