A commercial break is a pause between television shows or during one in which television commercials are aired succesively. Usually in North American television, a half hour show which is in actuality only 22 minutes without commercials, supports two, 3 to 4 minute commercial breaks during the show and approximately a 2 minute commercial break before and after. A standard commercial break for a half hour show consits commonly of comercials which vary in length most often from 30 seconds to a minute as television networks charge advertisers by 30-second intervals. In other countries the convention varies as in Japan shows only boast one long commercial break which usually divides the show equally.