An event is an action or activity during a specific period.
Event is a fundamentally useful term for designing and planning activities, including meetings and sequences of activities such as conferences and conventions. It's also fundamentally useful for reporting specific instances of action and activity. (Thus, event is specified as a key type of governance resource in Inclusive Organizing.)
The period during which an event occurs is often defined directly as an interval of time, but it can also be indirectly based on prerequisite actions. Examples: Event X starts on May 11 at 9am and ends on June 3 at 4pm. Event Y starts when L amount of preproduction remuneration has been generated, and ends when Action R has been completed.
In many or most cases, non-chronologically defined events are located purely by their position in a planned sequential process. For example, a recipe typically describes a linear sequence of cooking events.