That's when he'll be officially presented, to thousands of horse lovers, as the Guinness World Record-holder for world's tallest living horse.
The 9-year-old Belgian gelding from Smokey Hollow Farm near Poynette stands 20 hands, 2.75 inches - that's one quarter inch short of 6-foot-11 - from the bottom of his unshod hooves to his withers. He's taller than the previous record-holder, a Clydesdale from Texas named Remington, who's 20 hands tall.
Jerry Gilbert, co-owner of Smokey Hollow Farm, said a certificate from Guinness World Records in England arrived at the farm, by express delivery, in late March.
But Jake's coronation as a world record holder will officially take place Friday, at the Midwest Horse Fair, scheduled for Friday through Sunday at the Alliant Energy Center, Madison.
The official announcement will be made just before the Professional Rodeo Cowboys Association Rodeo, scheduled for 7:30 p.m.
Jake also will appear - along with his sidekick from Smokey Hollow Farm, a miniature stallion named Nemo - at the Kids Korral throughout the show.
Gilbert said people are welcome to take Jake's picture, but probably won't be allowed to stand next to him for a height comparison, because Jake, like many horses, may not be accustomed to strangers.
Gilbert said people who view Jake at the Kids Korral will be invited to contribute to the Ronald McDonald House in Madison in Jake's honor. It provides a "home away from home" for families of children younger than 18 who are undergoing medical treatment in the Madison area.
According to Gilbert, the Midwest Horse Fair was chosen as the place where Jake would make his debut as a record-holder because the show long has been a favorite of the people at Smokey Hollow Farm.
The event, which attracted more than 52,000 people last year, features more than 500 exhibitors, numerous horses and educational seminars on topics ranging from "A Child's Perspective on Training and Riding Horses" to "Training and Properly Harnessing a Driving Horse."
Daily admission costs are $10 in advance or $12 at the gate; weekend passes are available for $27 in advance or $36 at the gate. Children 7 and younger are admitted to the show free, though children will need tickets for the nightly shows, including the rodeo.
Meanwhile, Gilbert is awaiting Big Jake's official appearance in the Guinness Book of World Records.
"He's not guaranteed to be in the book," he said. "The 2010 edition may have already gone to press, but maybe he'll be in the 2011 edition."
Another record in the works?
As far as Jerry Gilbert knows, Guinness World Records has never documented the world's tallest team of horses.
If they ever do, then Smokey Hollow Farm might garner its second world record - and Big Jake, already confirmed as the world's tallest horse, could pair up with another Belgian horse, Almighty Bruce, to claim the team record.