A recent update on the official website of U.S. missions in India announces that the visa section at U.S. Consulate, Kolkata will remain closed to the public from November 10 to 14, 2014. This closure is attributed to renovation work that will be carried out during this period.
If any U.S. Visa applicant has scheduled his visa interview for one of these days, s/he will have to login to his/her profile and use the option to reschedule both the bio-metrics and the visa interview to a different date. This update also specifically instructs that there is no necessity to call the center or contact customer support in this regard. Applicants should simply login and reschedule the appointments. You may find this update here.