When will 'Game of Thrones' return for its final season: Our prediction

In terms of staying on an annualized schedule, Game of Thrones is about to break the wheel.

I'm going on record here, but hardly out on a limb: There is no way the show's finale lands in 2018, the first time in its run that HBO's crown jewel will skip a calendar year altogether. With a 2019 start all but assured, I've looked into the future -- and I see a specific date with perfect clarity.

And Marvel's untitled Avengers finale has something to do with it.

Now, there's a bit of deduction involved here, but mostly it's just common sense: Game of Thrones' production schedules have been steadily fattening over the seasons, from around four months per shoot to a little over six months for Season 7. That extra-long production forced HBO to shove off its traditional mid-Spring start this year, into deeper summer waters -- not such a bad call when you look at those record ratings.

Rumor has it that production on Season 8 begins in October (two months later than the start of last year's shoot, which lasted into February). And get this: Sources are telling THR that the final shoot could drag into next August, giving them something like 10 months' worth of material.

Season 7's six-month shoot -- the longest yet -- was given five months of postproduction time to hit the July target. The raw footage from a 10-month shoot will surely need more time to render, even if it's only six episodes (which are expected to be more than the usual 60 minutes but less than 90, the point after which principal actors' salaries are pro-rated -- a prohibitively expensive proposition).

So even if they do wrap late next summer, the earliest HBO could logistically drop the final season would be January or February -- and they're not dumping the biggest episodes of TV in history into that dead zone. They'll be fine to wait for their traditional March/April start.

Game of Thrones history would dictate something like a Sunday, March 31, 2019 start -- a little on the early side, but the same date as Season 3. And that gives them seven months of postproduction and marketing time, just about right.

But here's where The Avengers comes in.

Marvel's as-yet untitled Infinity War sequel -- the absolute culmination of all the Marvel films before it -- will open Friday, May 5, 2019, and absorb an enormous amount of pop-culture energy on its opening weekend. If Game of Thrones started on March 31, the finale of the six-episode season would fall on May 7, opening weekend for Marvel mania.

The most logical move: Move the start of Season 8 up one week -- to Sunday, March 24, 2019 -- which puts the series finale on April 28.

That keeps the whole series clear of Marvel, Star Wars Episode 9 (May 24, 2019), and all the other blockbusters set to come early that summer, which they'd slam into with a mid-April bow.

If I'm right, and 3/24/19 is indeed the date they choose, that will put 1 year, 8 months and 8 days in between Game of Thrones season starts -- by far the longest stretch of time so far, eclipsing the 1 year, 2 months and 22 days in between seasons 6 and 7.

All the more reason to think they'll opt for just a tad early -- the earliest calendar-date start in Game of Thrones history.

Isn't winter long enough?