The overnight programming, from midnight to the beginning of drive time, is generally low-key music with quiet, if any, announcing. Some stations play documentaries or even infomercials, while some others play syndicated or voicetracked DJs. Complete automation, with no jock, is very common in this day part. It is not uncommon to play more adventurous selections during late night programming blocks, since late night is generally not considered significant for ratings, and are not subject to federal restrictions as stringently as during the daytime. Stations are permitted to sign off during this time; in areas where AM radio is still significant (especially in the United States), local stations may be required to either sign off or cut to low-power to protect clear-channel stations.