Future Perfect Tense

The future perfect tense is used to describe an action which, at a certain point in future time, will be considered a past and completed action.

Examples:

By next September 15 they will have visited thirty different states.

That is, at some point in future time, namely, September 15, the action of their visiting the 30 different states will be a past and completed action.

We will have finished all exercises in this book by June.

The future perfect tense is formed from the future tense of to have, used as an auxiliary verb and the past participale of the main verb.