Abstract: A device and a method for waking a user in a desired sleep state. The device may predict an occurrence when the user will be in the desired sleep state, such as light sleep, and wake the user during that predicted occurrence. In one embodiment, a user may set a wake-up time representing the latest possible time that the user would like to be awakened. The occurrence closest to the wake-up time when the user will be in light sleep may be predicted, thereby allowing the user to sleep as long as possible, while awakening in light sleep. To predict when the user will be in the desired sleep state, the user's sleep state may be monitored during the night or sleep experience and the monitored information may be used in predicting when the user will be in the desired sleep state.