Abstract: The present invention discloses a time passage indicating apparatus which comprises a substrate, a background layer on the substrate, and a time passage indicating layer on the background layer. The background layer and the time passage indicating layer bond to each other through a first and second polymer binder. The background layer displays a background color. The time passage indicating layer displays an initial color in an initial state that is different from the background color, and a final color in a final state that is substantially the same as the background color, so as to indicate the end of a time period where the time passage indicating layer transforms from the initial state to the final state.