The future perfect continuous is used to project ourselves forward in time and to look back. It refers to events or actions in a time between now and some future time are unfinished. It is most often used with a time expression.
The future perfect continuous is composed of two elements:
The future perfect of the verb "to be" (will have been) + the present participle of the main verb (base + ing)
She will have been living in London since 2013.
Will it have been raining for six days?
By 2018, they will have been living in that house for 10 years.
Next month he will have been working here for 10 years.
When his father returned home at 9.00 p.m, he will have been learning English for five hours.
By the next year, I will have been working as a manager for 14 years.
We will be making a rest stop in half an hour, because you will have been driving the car for 8 hours by then.