A Los Angeles firefighter received $300,000 in overtime pay in one year by working more hours than actually exist in a single year.

Donn Thompson augmented his $92,000 salary by more than a quarter of a million dollars in 2017, Reason magazine reported, citing data from Transparent California, a project of the Nevada Policy Research Institute.

It wasn’t a one-off payout, as Thompson earned over $1 million in overtime pay over the last four years.

But the math behind the pay doesn’t add up. It would have required the firefighter to work 9,280 hours in a year, despite there being 8,760 hours in a single year.

The magazine crunched the numbers and claimed that the firefighter earned his base salary of $92,000 by working 2,912 hours at an hourly rate of $31.60. For overtime hourly rate, Thompson would earn $47.40, meaning that in order to receive $300,000 in overtime pay for the whole year, he would have had to work 6,370 hours – bringing the total hours worked to 9,280.

Robert Fellner, director of the institute, said the firefighter’s ability to work that many hours “boggles the mind” and said that Thompson was likely taking advantage of generous contract provisions that boost overtime pay above the typical rate.

Thompson is reportedly known for mastering the way to max out overtime pay. Between 1993 and 1995 he earned nearly $220,000 in overtime, a 1996 Los Angeles Times article reported. Thompson said at the time that most overtime hours are linked to covering for other workers at the stations and not to “fires or other emergencies.”

In 2008, Thompson earned nearly $180,000 in overtime pay, the Los Angeles Daily News reported, noting that the L.A. fire department's overtime budget skyrocketed by over 60 percent in a decade.

Thompson justified his pay a few years ago, saying he "basically lived at the station” and worked hard to earn it.

"The first thing [people] think of is firefighters sitting around at the station, but they're not just handing out free money over here," Thompson told the San Diego Union-Tribune. "I'm working hard."