A dosage cap records and displays dosage information about a medicine, including, the projected time that the next dosage of medicine is needed, the time interval between numerous administrations of the medicine, the time and/or date that the last dose was administered, the current daily intake amount, the date the dose was administered, or scheduled administration of the medicine. The time and date of the last dosage of medicine administered can be reset and updated when a subsequent dose of medicine is administered. The cap secures over a medicine container lid to provide easy visibility of the dosage information to a user. A shaft extends downwardly from the cap to secure the cap to the medicine container lid by penetrating the lid with a sharp point. A fastener attaches to the end of the shaft for securing the cap to the medicine bottle lid.