1. May I borrow this book?

- Sure. Just remember to give it back in a week.

2. May I borrow this book?
- Sure. Just remember to give it back within a week.
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In this short dialogue, does 'in' mean 'within'? Or are both different?

1 answer

They both mean pretty much the same. The second one seems to carry the meaning of "the sooner, the better," but basically they're about the same.