### Clue: A date coming up in the theatre (5)
### Answer: ARENA 
 ### Explanation: Definition: theatre
  **Reversal of**(coming up, in a down clue) [AN(alternative to the article "a") ERA(a non-specific date, more a period, as in "carbon-dating will tell you which era that fossil came from").
Defn. and Answer: An area in which conflict, activity or endeavour is conducted.