When Does it Stop Becoming "Breaking News"?

Can someone tell me when does "Breaking News" stop becoming breaking news?

1 hour? 2? 6?

We don't know the answer, but according to MSNBC, 9+ hours is still OK to call it "Breaking News."

9 hours after the Supreme Court made the ruling on Obamacare ...MSNBC was still calling it "breaking news." 

Shaking my head.