Opher asks in his blog, Is there a non-event event ? on absence as a pattern.
All “non-event” examples that the event processing community has offered, to date, have been based on the premise that an event is created when something does not happen based on time, schedule or a timer – and many seem to want to refer to this as a “non event.”
Opher is now calling this situation an “absent event.”
In my opinion, the correct term should be a “time-based event” because the event is triggered by a timer or similar time-based object; the term “non-event” should be dropped from the event processing glossary.
The Complex Event Processing Blog 
Hello Tim.
Time-based event does not have to the fact that event does not happen within a certain time interval, there can be many other types of time-based events – such as: at the end of the hour – if there exists an event that satisfies some condition then “detect a pattern” – the time-based refers to WHEN the event is detected, while the absence event refers to WHAT is the pattern that should be detected — the fact that in any time-point over this interval a certain event DID NOT OCCUR. A good alias of “absent event” may be “time-out event” – the name is used a lot in “wait” situations.
cheers,
Opher
Hi Opher,
Yes, I agree that the term time-based event is larger than only time-outs. Time-outs are a subset of timer, or time-based, events, as you kindly point out.
“Timeout event”, or “timeout-based event” is nice (and more specific) term, as you suggest.
Yours faithfully, Tim