Many people know how to say tomorrow, next week, yesterday, and last week. These phrases indicate a time span of 1 unit (i.e. "day", "week", "month", "year") into the future or past. However, when you want to talk about two time units into the future or path (i.e. two months, two weeks, two days, etc.) we have a special grammar pattern to describe it. For example:
  • Next week I will be saying in Osaka, and the week after next, I will travel to Kobe.
  • Next month will be very busy for us, but the month after next we should have more time to discuss this.
  • I hope to have the business online by next year, and to be making profits by the year after next.

These are ways of talking about things to happen in the future. When you want to refer to the past, you can use the following, similar pattern. For example:
  • Last week was very cold, but the week before last was quite warm!
  • The year before last, I traveled to France to study French.
  • Does anyone remember the name of the man who called the day before last?

We do NOT say the noun twice, such as "The week after next week" or "The month before last month", though it is understood that way by the listener.

(Note that the above patterns can be used with most time units, including the hour after next, the minute before last, etc., though it is most commonly used with the units of "week", "day", "month", or "year".