Which one is grammatical? Or is this a question of style?
- In a time when someone else is sent to clean up our mess.
- In a time where someone else is sent to clean up our mess.
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in terms of the concepts of 'time' and 'space', 'when' refers to 'time' and 'where' refers to 'space' so 'in a time when someone else is sent to clean up our mess' would be more correct in this context.