Go Early: Would you rather start out in the dark or end in the dark? You can always sleep after the hike is over. Getting on the trail at 3 or 4 in the morning sounds extreme, but it makes sense.  High altitude hikes can be prone to afternoon thunderstorms.  It’s much better to reach the summit by 10-11am and be out of harms way by the time of afternoon thunderstorms. Another benefit of heading out at or before dawn is cooler weather.  Less heat means less sweating, therefore less water needed and a lighter load.