PURPOSE: To prevent interruption of storage processing in every transmission data reception and input day by deleting used transmission data in the period to the preceding day in parallel with reception and input operation at the time of day switching processing.

CONSTITUTION: Functions d-5 and d-13 are newly constituted which control the traffic of the transmission data reception and input processing and the deletion request of used transmission data in the period to the preceding day. A function which issues a day switching operation request as an opportunity of day switching processing is started by timer setting. It is unnecessary for an operator to input the day switching request by a command, and the labor of operation is reduced. Used transmission data can be deleted in parallel with reception and input of new transmission data, and the alternative input of received and inputted transmission data or the reinput work of alternatively inputted transmission data is unnecessary during the processing phase switching due to system restart, and the labor of operation is reduced furthermore.