When I first heard this, I had a flashback to a dinner party at a friend's house a few years ago. I'm not going to mention this friend by name so as not to cause embarrassment, but she is a terrible cook. Everybody enjoyed the time with friends, but nobody enjoyed the dinner. The instant mashed potatoes were runny enough to be a soup, the meat was drier and tougher than a leather jacket, and I learned that peanut butter and lime are flavors that do not mix well in a dessert. My wife and I politely ate enough as to not be rude while we were there, but quickly pulled some leftover pizza out of the fridge as soon as we got home.
That's how it is with our schools right now. As long as we are providing education that focuses on test-prep, teacher directed lecture, irrelevant canned textbook lessons, and treating students as data that can be manipulated; more of it is not going to fix any of our problems. In fact, it will probably make them worse.
Just like forcing me to eat more of that brisket would have had awful consequences, forcing students who (correctly in most cases) have learned that school is irrelevant to endure more of it will not make the problem better.
As has been pointed out by many others covering this story before, American children already spend more time in school than their peers in Finland, Japan, South Korea, and other countries that we perceive as being "high-performing." More time in school has not made us better in the past. It won't make us better in the future.
What will make us better is to change our approach to education. Make it student-centered. Make it relevant. Make it about learning and not about test-taking. Because, if we do it right and teach our children to love to learn, they'll do it all the time.
They won't need to be in school all those extra hours in order to learn. They'll be doing it everywhere they go and in everything they do.
And when that happens, other countries will be trying to figure out how they can design their education systems to be more like ours.