A computing device incorporates a user sensor to signal when a user is moving or within a specified proximity of the computing device. If the user is not present, the computing device will go into a low-power mode. A real-time clock is programmed to interrupt at user indicted event times and dates. If a queued event occurs, the computing device samples the user sensor and begins notification procedures if the user is present. If a queued event time occurs while the user is not present, then the computing device enters or stays in the low-power mode. If the user sensor indicates that the user is present, the computing device notifies the user of the pending event and any missed events. The computing device may require a user code before normal operation is activated following a transition to an indication that the user is present.