Google DeepMind CEO Demis Hassabis revealed in a recent video interview with Fortune that he follows an unconventional sleep schedule, splitting his day into two distinct work periods. Despite aiming for six hours of sleep, Hassabis said he functions best during what he calls his "second day" of work, which begins around 10 p.m. and runs until 4 a.m. "I do try and get six, but I have unusual sleeping habits," Hassabis said. "I sort of manage during the day." He emphasized that less than six hours would negatively impact his cognitive performance, underscoring the importance of sleep for brain function. Hassabis, who co-founded DeepMind in 2010 and led its acquisition by Google in 2014, now heads Google DeepMind—the merged entity of DeepMind and Google Brain. The lab is behind major AI tools like Gemini and Nano Banana. In 2024, Hassabis and his colleague John Jumper were awarded the Nobel Prize in Chemistry for their groundbreaking work in predicting protein structures using AI. He described his typical day as highly structured, filled with back-to-back meetings at the office, with minimal downtime in between. After returning home, he spends time with his family and eats dinner. Then, he begins his second workday, dedicating the late-night hours to deep thinking, creative problem-solving, and research—tasks he finds most productive. "I can't imagine being creative at four in the morning. But, I come alive at about 1 a.m.," Hassabis told Fortune’s Alyson Shontell, echoing a sentiment he previously shared in a 2017 BBC Radio interview. His routine has been consistent for about a decade. Hassabis’ approach aligns with patterns seen among other high-profile tech leaders. Elon Musk has said he functions optimally on about six hours of sleep, and in 2018, he admitted sleeping on the floor of a Tesla factory during a critical production phase. Meanwhile, Salesforce CEO Marc Benioff has stated he averages around eight hours of sleep, highlighting the wide range of personal habits among top executives.