PURPOSE: To improve operability of the schedule updating device.

CONSTITUTION: A pre-change schedule management table 1-1 preserves pre- change schedule information. A post-change schedule management table 1-2 stores schedule information which is being inputted and changed. First of all, a schedule information acquisition means 1-3 obtains the pre-change schedule information in the lump from a sever, and stores it in the pre-change schedule management table and the post-change schedule management table. Subsequently, an input/output control means 1-4 displays the contents of the post-change schedule management table in an output device, receives update information from an input device inputted based on this display and updates the contents of the post-change schedule management table, and displays the result of updating in the output device. Next, a command table generating means 1-6 compares the contents of the pre-change schedule management table with the contents of the post-change schedule management table, generates a command table and issues a command to the server through a server access means 1-7.