5.130 'in' and 'within' for end of a period

'In' is used to indicate that something happens or will happen before the end of a certain period of time. In more formal English 'within' is used.

• Can we get to the airport in an hour?
• That coat must have cost you more than I make in a year.
• The face of a city can change completely in a year.
• Some may form the basis of a new anti-Aids drug within a year or two.

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'In' and 'within' are also used to indicate that something only took or takes a short time.

• The clouds evaporated in seconds.
• What an expert can do in minutes may take you hours to accomplish.
• Within a few months, the barnyard had been abandoned.