You should always carry a headlamp or a flashlight and some extra batteries. You want enough light that you can walk with after dark if you’ve been delayed, or that you can camp with if you decide to stop and wait until daylight.
Even if you start hiking at 6:00am and will be finished by 11:00am, still take your flashlight. An injury or bad weather can easily keep you out through the night. LED headlamps are very bright, very small, inexpensive, and last a long time.