Disclosed is a device for reminding a user to drink from a container. The device may be attached to either the cap of the container or may be assembled inside the cap of the container. The device includes a housing, a battery, a printed circuit board, a battery holder, a button, an upper cover, a controller for storing a reference time, a reference timeout value and generating reminding signals, at least one output unit connected to the printed circuit board to produce output signals on receiving reminding signals from the controller, a tap button placed in the indent to meet the button on receiving tap from the user. Further, the controller stores the reference time on receiving the tap from the user and generates reminding signals for the user to drink from the container when the user fails to either tap the button again or remove the button from the spout in duration of the stored reference timeout value from the reference time.