Sales data processing device and program

A computer-readable recording medium having a computer program stored thereon which is executable by a computer in a sales data processing device which executes sales data processing by referring to a date and time, wherein the sales data processing device comprises:

• (i) an electromagnetic wave clock section, which clocks a date and time, receives a time signal containing date and time information that is transmitted from a time signal transmission station, and corrects the clocked date and time based on the received time signal, and (ii) a clock section which clocks a date and time for the sales data processing, and wherein the program is executable by the computer to cause the computer perform functions comprising:
• determining whether or not sales data processing is being executed;
• determining whether the sales data processing device is in an energized state in which power is supplied to the sales data processing device by a main power source, or in a standby state in which power is supplied to the sales data processing device by a secondary power source due to disconnection from the main power source;
• and
• when it is determined that the sales data processing device is in the energized state to be operated by the main power source and when it is determined that the sales data processing device is in a state of not executing the sales data processing, selecting a time correction method in which the time signal is received at regular time intervals by the electromagnetic wave clock section, and in which the date and time of the clock section is corrected based on the time signal received at the regular time intervals.