An event was defined as a gathering for purposes of celebration, marketing, education, or any other common interest.
The symbol for time was a t. This symbol was used for counting down to an event, as in "T-minus", or for measuring time after an event has occurred, as in "T-plus". (TOS: "Assignment: Earth", TNG: "Contagion")
Spock was impressed by John Gill's treatment of Earth history as causes and motivations, rather than dates and events. (TOS: "Patterns of Force")
