To set a highly accurate time information in a printer without a bult-in clock.

A time storing module acquires the present time with reference to a temporary present time storage part (Step S32), calculates a difference A between the second time information stored in a second print job transmitting time storage part and the present time, and determines whether the absolute value of the difference A is in a predetermined time range (Step S34). When the difference A is within the predetermined time range, it is determined that the accuracy of the first time information and the second time information is high because there is no inconsistency between the first time information and the second time information. The predetermined time range is a value obtained by multiplying the elapsed time showing a job receiving interval by a predetermined coefficient and adding the calculated value to a value of fixed time. When the absolute value of the difference A is within the predetermined time range, the first time information is used as the start time of use and the second time information is held as the end time of use.