What is the difference between:
The package will be delivered in two days' time.
The package will be delivered within two days.
Are they the same or different?
If today is Monday, and a company tells me:
Your package will arrive in two days' time.
then I will expect the package to arrive on Wednesday.
However, if today is Monday, and a company tells me:
Your package will arrive within two days.
then I will expect the package to arrive on Tuesday or Wednesday.
If we change the verbiage from two to four then:
In other words, "in two days' time" is typically a prediction, while "within two days" specifies an upper limit.
in two days time = when the delivery will occur
within two days = implies there is a limit. No later than two days.
You must do this task in two days. [usually, two days from some date or you have two days to do it.]
You must do this task within two days. [we don't know when those days will be and it sets a time limit on how long you can take.]
within two days = within 48 hours. [sets a limit]
in two days = in 48 hours. [says when or describes how many days are needed]