An image forming system includes: a server; and an image forming apparatus, in which the server acquires divided-images obtained by dividing an original image, and provides the divided-images to the apparatus, acquires a dividing-printing-rule for determining which divided-image of the divided-images is printed at which position, and provides the rule to the apparatus, information on a divided-image to be printed and a printing position of the divided-image to be printed being described in the rule for each time when printing the image to be printed, and provides present time to the apparatus as time information, and the apparatus acquires the divided-images to be printed, the rule, and the time information from the server, selects, based on the time information and the rule, the divided-image to be printed from the divided-images and determines the printing position of the divided-image to be printed, and prints the selected divided-image at the printing position.