A bookmark (12) uses an integrated electronic timer circuit (18) to track reading time. A flat substrate (14) marks the page of the book. A header (16) is integral with the substrate. The header has a cavity for housing the electronic timer, a display (20) for displaying the timer count value, and a plurality of control buttons (22-28) for controlling the electronic timer. A sensor (54) can sense an external condition such as light or touch to control the electronic timer. A light source (56) is provided in the header. The substrate may contain a magnifying viewing port. The electronic timer has a memory (42) for storing the timer count values for individual and cumulative reading sessions.