A device for controlling displaying of a user plan for inputting schedules in a calendar includes a display unit displaying a plan window for inputting one or more pieces of schedule information in a calendar, and a control unit controlling the display unit to display a predetermined window including schedule information, which a user intends to input in the plan window, in a predetermined area of the display unit, and controlling the display unit so that when the schedule information included in the predetermined window is selected and moved on the calendar in response to input from the user, the selected and moved schedule information is inputted as a time block at a date where the schedule information has moved on the calendar.