A communication device includes: a time zone determiner section that identifies a switching point of time of communication time zones based on a clock time and determines whether the communication time zones are switched based on the clock time and the switching point of time; a channel switch section that designates a communication-target channel by switching the communication time zones at the identified switching point of time; a transmission processor section that performs a data transmission using the communication-target channel designated, and prohibits data transmission from being performed for a predetermined transmission prohibition duration time before and after the switching point of time; an error assessor section that assesses an error amount that is a degree of an error of the clock time against the reference clock time; and a transmission prohibition-time adjuster section that increases the transmission prohibition duration time as the error amount increases.