Ten days

"With the help of stolen U.S. technology, China has developed at least three types of high-tech weapons to attack the electric grid and key technologies in a “surprise Pearl Harbor” assault that could send America into a deadly blackout, according to a new analysis."

https://thereport.be/article/?u=https%3A%2F%2Fwww.washingtonexaminer.com%2Fwashington-secrets%2Fchina-deploys-weapons-to-fry-us-electric-grid-eyes-high-tech-pearl-harbor-attack