If everyone did it, it would work fine.

Business hours : 1 hour after sunrise until 10 hours after sunrise.

Even without that, many of us have flexible hours and can either start work earlier, or just do something before work when we have time. Waking up early in the summer means you can catch a bike ride or take a short run or hike before work. Since it's too hot in the afternoon/ evening this works quite well for much of the country.