But crawling into your sleeping bag at 6 30 ...doesn't mean you'll sleep until daylight - which, on monday, wasn't until after 7 AM.
On most winter backpacks in the NE in December - February, you don't want to sleep till daylight anyway. Waking, making breakfast, cleaning up, breaking down camp, and packing for the day (and trying to stay warm during that process, esp fingers and toes) is going to take several hours. Since the daylight hours are so few, you pretty much want all of that done by 7am, so waking at 4:30a is a benefit.