Dinner will be served within an hour

I consulted Reverso for the translation of two propositions from this lesson:

1. Dinner will be served within an hour

2. Dinner will be served in an hour's time

Both produce the same french frase: 

Le dîner sera servi dans une heure

My question: why Kwizbot showed error to my translation into English that read “Dinner will be served within an hour”