The former Ticketmaster CEO took to Twitter (TWTR) to encourage would-be holiday-takers to fully utilize the last two weeks of December, when many companies are closed or at reduced staffing and get a head start on beating the competition in 2018. “Get to work,” Hubbard urged his 18,000 Twitter followers.

Whatever you’re hustling for, take note: most people/companies are shut down until ‘18. That means you get 2 extra weeks to outwork your competition. That’s 3.8% more time. For perspective: Usain Bolt won his gold medals running 1.2% faster. These 2 weeks are a gift. Get to work.

— Nathan Hubbard (@NathanCHubbard) December 18, 2017

A dip of work efficiency is a well-known phenomenon during the late winter months, with workers feeling more stressed and less productive as the New Year inches closer. In a survey of 2,000 workers in the U.K., human resources consulting company Peakon found that 61% feel checked-out and less productive at work as early as November.

Hubbard’s appeal to get back to the grindstone hit a nerve, with Twitter users criticizing his advice, saying that it was emblematic of the the “always-hustle” attitude popularized by Silicon Valley start-up culture, as well as unhelpful and “unhealthy.” Many insisted on the importance of taking time to mentally recharge to avoid burning out at work.

But Hubbard may be tapping into a cultural shift: more of us are working during the holidays, and we aren’t working less efficiently.

A study from the Society for Human Resource Management found that 84% of offices plan to remain open during for the week between Christmas and New Year’s— so there may be more competition in the field than Hubbard predicts. And according to a survey by file-sharing firm Egnyte, while one-third of workers take time off during the last week of Dec., companies report only a 5% decrease in productivity. Business services, healthcare, media, and education companies may even see productivity increase by as much as 59%.

For more about the modern workplace, watch Fortune’s video:

Hubbard took the backlash with good humor, saying that he would be spending time with his family in Hawaii and “hustling” to lose some weight. Maybe his closing advice is the most welcome: “Make your own choices. Do your thing,” whether it’s or hard work or celebrating the holidays.