To provide a calendar wherein a plurality of months are provided on one surface of the calendar, a window is provided in the calendar, and a decoration part having a picture is placed separately on a back side of the window of the calendar to display the picture, and the picture can be replaced each month even when the same decoration part is used.

A plurality of different calendar display parts (for example, a plurality of months) are provided on one surface of a calendar part, and regarding the picture displayed through the window provided on the calendar part, the display part showing the picture is rotated on the back side of the calendar part, and thereby, the picture can be replaced with the picture desirably corresponded to the calendar display part to be used now (for example, this month) among the plurality of different pictures.