Keeping a sleep diary is also a good way to help calculate and keep track of your sleep efficiency, which is the amount of time you spend in bed vs. the amount of time you spend sleeping. If you are practising Sleep Restriction Therapy, then keeping a sleep diary is a must.
Sleep diaries can also be a useful tool to help health professionals diagnose why their patients are having sleep difficulties. So, if you are having sleep problems and need to talk to your usual health professional about your sleep issues, it may be a good idea to bring your sleep diary with you to the appointment.