T.J. Klune has ADHD, and he talks about his writing schedule as a direct response to it rather than a stylistic preference. The structure exists because, by his own account, he needs it to function.

The Direct Answer
He writes first thing every morning for four to five hours, protecting that block before publicity, marketing, or email get any of his attention.
Klune has said routine isn't optional for him. Given his ADHD, he needs it in order to function properly as a writer.

The Morning Belongs to Fiction

"I keep to a pretty strict schedule," Klune has said. "Given I have ADHD, I need routine in order to function properly. I write first thing in the morning for four or five hours." After that block ends, the rest of his day goes to what he's called "marketing, publicity, and an email inbox that never, ever empties no matter how long I spend on it."

The order is deliberate. Publicity and correspondence will expand to fill whatever time is available to them, so Klune protects the morning specifically because it's the part of the day least likely to get eaten by something else. He's described feeling "extremely fortunate" to write full time, a gratitude that sits alongside a schedule built less for inspiration and more for maintenance.

Ten Years of Writing Around a Day Job

That discipline predates his full-time career. Klune worked as a claims adjuster at Geico for a decade, from 2006 until February 2016, writing and publishing fiction on the side the entire time. His first novel, Bear, Otter, and the Kid, came out through an independent publisher in 2011, five years before he left the insurance job behind. For the fuller story of that transition and how it shaped his current routine, see the full T.J. Klune writing routine.

What You Can Steal