1. A non-transitory computer-readable recording medium on which an image processing program that is executed by a computer is recorded, the image processing program generating a data item for playback to be played back by successively arranging, in order of data and time of photography, plurality of image data items photographed by a plurality of cameras, the image processing program comprising instructions for: a reading process of reading the plurality of image data items and information regarding date and time of photography, the plurality of image data items having been photographed and recorded by the plurality of cameras and the information regarding date and time of photography being added to each of the plurality of image data items; a selection process of selecting one editing mode from a plurality of editing modes in accordance with a selection command output from an actuation member, the plurality of editing modes including at least an editing mode for displaying one image on a display monitor, and the one editing mode that is selected specifying an editing process for the plurality of image data items read by the reading process; an extracting process of extracting image data items of which the dates and times of photography overlap within a same time band from among the plurality of image data items that have been read; an image data item selection process of selecting image data items corresponding to the editing mode selected by the selection process as selected image data items, from among the plurality of image data items extracted by the extracting process; and a generating process of generating the data item for playback by successively arranging the selected image data items selected by the image data item selection process in accordance with the editing mode selected by the selection process.