I want to know the answer to the following question:
On what date was the Garde Nationale empowered to hoist a red flag to signal their intervention in a riot?
All the background I'm provided with is that "A law adopted by the new government on October 20, 1789 authorized the Garde Nationale to raise the red flag in the event of a riot, to signal that the Garde would imminently intervene.". Is that enough to answer the question?