While I was reading PEU about time-expressions (at, in and on) I faced with "
In can be used to say how soon something will happen, and to say how long something takes to happen". Meanwhile, the expression "in ... 's time" is used to show how soon something will happen, not how long something takes place. There is an example:
Ask me again in three or four days.
My question is whether the sentence
Ask me again in three or four days' time.
correct at all? If so, whether it has the same meaning as the first. I guess, it has... but I'm doubting.