An add-on timer for a medicine container is provided having a base plate affixed to the top of an existing lid, a housing overlaying and coupled to the base plate, and a timing unit within the housing. The housing is displaceable relative to the base plate by a person depressing or twisting the housing, which actuates a switch and resets the timing unit. A display indicates the elapsed time since the container was last accessed, to assist a patient in following dosage instructions.