The future perfect tense

The future perfect tense denotes action that will be completed at some definite time in the future. The future perfect tense is seldom used in informal speaking or writing.
The future perfect tense is formed by combining the auxiliary verbs shall have or will have with the past participle of the principal verb. Shall have is used in the first person, will have is used in the second and third person.
The italised words are in the future perfect tense.

By January, the committee will have completed the investigation.
I shall have crossed the river three times before noon.