Future Perfect Simple: Actions That Will Be Completed by a Certain Moment in the Future

Future Perfect: an action finished before a point in the future.

Form: will have + V3.

• By 8 p.m. I will have finished the report.
• She will have left by the time you arrive.
• In two years they will have built the bridge.

Often with by, by the time, in two weeks. Do not confuse it with Future Continuous (in progress) or Present Perfect (now).