Alex Tabarrok, a professor of economics, writing in Marginal Revolution »
To get an appointment for a Visitor Visa in New Delhi, for example, takes 291 days. In Mexico City the wait time is 581 days. In Nairobi, Kenya it takes 664 days! Moreover, “It should be noted that the “Wait Times for a Nonimmigrant Visa to be Processed” information by country does not include time required for administrative processing.”
The US State Department website states »
Advance travel planning and early visa application are important. If you plan to apply for a nonimmigrant visa to come to the United States as a temporary visitor, please review the current wait time for an interview using the tool below. Not all visa applications can be completed on the day of the interview…