The analog shutdown for full-power TV stations was completed in mid-2009, with several stations ending analog transmissions well before the June 12, 2009 deadline. (Many transitioned on the original February 17 date.) In most cases, at least one station in each media market continued analog broadcasts for up to 30 days afterward as an "analog nightlight"—prohibited from broadcasting regular programming, but allowed to transmit information on how to obtain and connect a converter box to receive digital programming (and send Emergency Alert System broadcasts.). This allowed viewers who had not converted by the deadline to receive at least one channel that would explain the absence of the other analog channels. The half-hour public service announcement with English and Spanish segments seen on most such stations was produced by the National Association of Broadcasters.