Looking Back from the Future
Advanced nuances:
ā¢ Past Certainty: "He will have arrived by now." (Meaning: I am sure he has arrived). This is a modal use of "will" + perfect aspect, referring to the past, not the future.
ā¢ Completion before a future moment: "By 2050, we will have colonized Mars."
ā¢ Duration up to a future point: "We will have been married for 50 years next month." (Note: This is Future Perfect Simple used for state verbs/passive, whereas action verbs often use Continuous).