Dans vs d'ici

Question

What is the difference between "Vous recevrez une réponse d'ici une semaine." and "Vous recevrez une réponse dans une semaine."? Can they be used interchangebly?

Maarten Kamp · Accepted Answer

Emre, my understanding and interpretation:
Je le ferai (I will do it)
“d’ici une semaine” - by one week, or within one week (I am not saying when but giving you my deadline for completion)
“dans une semaine” -  in 1 week (I will do it then, not before)
“en une semaine” - over 1 week. (It will take me a week to do)
https://progress.lawlessfrench.com/revision/grammar/talking-about-time-when-to-use-en-versus-dans-prepositions-of-time?
https://progress.lawlessfrench.com/revision/grammar/by-point-in-time-d-ici?