Thanks to other series releasing either their finalized (IMSA) or provisional (Pirelli World Challenge) 2017 calendars, or tracks announcing their own dates, we already know most of the 2017 Verizon IndyCar Series schedule – which series officials hope to release later this month.

A couple weeks ago, we forecast what the announced dates on the Verizon IndyCar Series calendar could look like, as part of a number of others that were already out.

Those dates are below:

INDYCAR

St. Petersburg, March 9-12, 2017

Long Beach, April 7-9, 2017

Grand Prix of Indianapolis, May 11-13, 2017

Indianapolis 500, May 28, 2017

Detroit, June 2-4, 2017

Road America, June 25, 2017

Iowa, July 8-9, 2017

Toronto, July 13-16, 2017

Since that point, we’ve had three other dates released, by way of the provisional World Challenge calendar out last week at Mid-Ohio, and two more today by way of IMSA’s calendar release – via some additional IMSA content.

The additional World Challenge date confirmed is Mid-Ohio, on the last weekend of July, July 28-30. That’s in addition to confirming its presence at St. Petersburg, Long Beach and Road America, with the possibility of Sonoma continuing.

Then we got two more dates out of IMSA today, the Barber Motorsports Park and Sonoma Raceway dates.

Those dates are:

Barber, April 21-23, 2017 (Porsche GT3 Cup, Prototype Challenge)

Sonoma, Sept. 15-17 (Porsche GT3 Cup)

“I think it’s a reflection of the quality of those championships and the show that they put on, the quality of the teams, the drivers,” IMSA President Scott Atherton told NBC Sports of adding IMSA content to those two IndyCar weekends. “It’s incredibly competitive racing. The cars are sexy, they’re fast, they make great sound. Everything about them is attractive.

“We have good relationships with IndyCar, we have great relationships with those promoters. There’s no issue there. They’re smart promoters that recognize an opportunity to bring an interesting element into what would otherwise be an open-wheel weekend. And it makes a lot of sense for us as well.

“We’re in a situation with so many platforms that it’s very difficult for us to accommodate all of the platforms on all of our big weekends. So by having the opportunity to place selectively some of these other championships within other significant weekends, IndyCar weekends are a great fit, Barber Motorsports Park, Sonoma, all perfect venues for this type of championships and those type of cars.”

So what does this mean for the remainder of the IndyCar schedule? Several things, including that at least 12 race dates are locked in.

This means Phoenix is locked in either for the first or last weekend of April. If it doesn’t want to conflict with the Final Four which occurs on Saturday, April 1, that would shift it to Saturday, April 29. Even though logistically speaking, it would make more sense to be in Phoenix the first weekend in April, then Long Beach the next weekend.

Second, the outstanding race dates from 2016 yet to be determined beyond Phoenix – which we know is back – are Texas, Pocono, Watkins Glen and potentially Gateway, which according to NBCSN contributor Robin Miller in a RACER.com piece appears poised to rejoin the schedule. Gateway officials were present at the Indianapolis Motor Speedway earlier this year.

Provided Texas is in its usual post-Detroit, non-rain delayed slot, that would put it on Saturday, June 10.

Pocono and Watkins Glen are the question marks but given the Mid-Ohio to Sonoma gap, you’d expect to see two if not all three of Pocono, Gateway and Watkins Glen slot into that time frame.

Also something else to note? Where do Mazda Road to Indy races slot in. The addition of IMSA and World Challenge content on some of these weekends limits the potential for all three Mazda Road to Indy series to run on the same weekend. Expect Mazda Road to Indy on most IndyCar weekends but the details of which of the Indy Lights Presented by Cooper Tires, Pro Mazda Championship Presented by Cooper Tires and Cooper Tires USF2000 Championship Powered by Mazda series to be sussed out later.

Cancel out the possibility of the much-discussed yet never-implemented international races and you’ve already got most of your 2017 IndyCar schedule ready to go, as you see below.

2017 Verizon IndyCar Series dates as we know them, plus additional content

St. Petersburg, March 9-12, 2017 (Pirelli World Challenge)

Long Beach, April 7-9, 2017 (IMSA WeatherTech Championship, World Challenge)

Barber, April 21-23, 2017 (IMSA Porsche GT3 Cup, Prototype Challenge)

Grand Prix of Indianapolis, May 11-13, 2017

Indianapolis 500, May 28, 2017

Detroit, June 2-4, 2017 (IMSA WeatherTech Championship)

Road America, June 25, 2017 (World Challenge)

Iowa, July 8-9, 2017

Toronto, July 13-16, 2017

Mid-Ohio, July 28-30, 2017 (World Challenge)

Sonoma, Sept. 15-17 (IMSA Porsche GT3 Cup)

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