The duration of an event is the length of time in which the event occurs.
The duration of an event is a function of both the extent of the change which characterizes the event, and the rate at which the change occurs.
The time it takes for a moving body to travel from one point to another depends on the distance traveled between the two points, and the speed.
Lifespan is the duration of activity which constitutes an event. The lifespan of a system is the overall length of time in which the system progresses through various changing states.
The lifecycle of a star, such as our Sun, is determined by the various stages of activity which evolve throughout its history, which may occur over billions of years. In contrast, the lifespan of a cumulus cloud in the Earth’s atmosphere, evolving from condensation through saturation and evaporation, may occur within a period of 15 to 20 minutes.
The time of an event has a finite duration as distinguished from infinity. Timelessness is an abstraction which corresponds to a complete absence of change.
The timelessness of an event is the absence of duration and corresponds to a time value of absolute zero.
Since there is no evidence of a complete absence of change within the universe, there is no corresponding state of timelessness.
The experience of timelessness is a psychological phenomenon which results from internalizing events within the brain.
He who has waited long enough, will wait forever. And there comes the hour when nothing more can happen and nobody more can come and all is ended but the waiting that knows itself in vain. – Samuel Beckett