I counsel our children to do their critical studying in the early hours of the morning when they're fresh and alert, rather than to fight physical weariness and mental exhaustion at night. I've learned the power of the dictum, "Early to bed, early to rise." When I'm under pressure, you won't find me burning the midnight oil. I'd much rather be in bed early and getting up in the wee hours of the morning.
Boyd K. Packer (1975). “Teach Ye Diligently”