A sleep diary, also called sleep log or sleep journal, kept by a patient at home for at least two weeks, while subjective, may help determine the extent and nature of sleep disturbance and the level of alertness in the normal environment. A parallel journal kept by a parent or bed partner, if any, can also be helpful. Sleep logs can also be used for self-monitoring and in connection with behavioral and other treatment. The image at the top of this page, with nighttime in the middle and the weekend in the middle, shows a layout that can aid in noticing trends