Depends on factors such as how soon you respond to NVC's requests, when a visa is available, etc.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.
The scheduling is not done solely by the NVC. It also depends on the availability of calendar "slots" available at the US Consulate at which the case is pending. I would say that a minimum of 1-2 months may pass before you receive notification.
This answer is of a general nature and should not be relied upon as final, nor is it intended as legal advice. A consultation with an experienced attorney is always the best way to go.