An image forming apparatus includes a fixing device disposed downstream from an image forming device in a recording medium conveyance direction to fix a toner image formed by the image forming device on a recording medium. The fixing device includes a pressing rotary body separatably pressed against a fixing rotary body to form a nip therebetween through which the recording medium bearing the toner image passes, and a moving assembly to move the pressing rotary body bidirectionally to press the pressing rotary body against the fixing rotary body and separate the pressing rotary body from the fixing rotary body. A controller controls the moving assembly to change a post-fixing pressing time period for which the moving assembly presses the pressing rotary body against the fixing rotary body after the recording medium bearing the toner image is discharged from the nip according to image data.