How long did the blackout in 2003 last?

The blackout in 2003, which affected parts of the northeastern and midwestern United States and Ontario, Canada, lasted approximately 2 to 4 hours. It began around 4:10 PM EDT on August 14 and most power was restored by 10 PM that same evening. Some areas experienced outages for longer due to the complexity of the restoration process. The event was one of the largest blackouts in North American history, impacting around 50 million people.