Winter backpacking: Hike nights, sleep days?

Why not hike all day and set up camp later at night (like at 10 p.m.)?

You should really only do this if you are hiking on a well maintained trail. I have passed by trail junctions that would have been very obvious in the day time but were almost invisible to me in the dark. I think navigation will be your biggest issue, especially with how overgrown the trails in the central coast can get. A gps would be very useful.
Most of my winter hiking is off trail and impossible to do in the dark so I know what it's like to face those long nights.
Bring good food, do real cooking, bring along good friends, and have a big roaring campfire and it's not so bad :)

I have never hiked all night long, but my experience with night hiking has been that you often see more wildlife or at least different wildlife compared to day hiking. A definite benefit in my opinion. Also, if you wake up late enough in the afternoon you could probably still manage to see sunrise and sunset during your hiking period, just in reverse order.

"you often see more wildlife"

You might not see more wildlife, but you may hear a lot. That takes us back to the discussion on audio recorders.

On a trip in August, I found myself hiking after 10 p.m. in pitch blackness. I heard an animal which I later identified as being a gray fox. I've never seen one in daylight.

–B.G.–

You see a lot of ominous orange eyes glaring back at you.

Seems like it would be a totally different experience than hiking in daylight. I'm generally taking in the scenery, checking out the plants, rocks, clouds, etc. I wouldn't be able to really do that in the dark even with a headlamp.. I bet it'd be a very unique experience and something you wouldn't forget.

Staring at a circle on light on the trail for 10 or 12 hours gets old fast.

It is very different. Got out of Saguaro Natl Park (Tucson AZ) the other day by moonlight as even the half-moon illuminated my shelter and surroundings. Since I couldn't sleep anymore, I hiked down about 2-3 hours in moonlight/early twilight. In high desert grasslands, I could pretty much see the trail even without headlamp and the surrounding. Keeping tabs on the trail parting the grass was surprisingly easy, but going over large flat bedrock was slow. Didn't have to worry about rattlesnakes in the cold going through the high grass either.

I took a few pictures but didn't really come out right until dawn started to break. A little photoshop shows how it looked:

Night hiking is a lot of fun and a completely different experience, but the novelty does wear off quickly.
My hiking buddy and I would drive late at night after work/school and show up to the pine ridge trail head in Big Sur at around 11 p.m. We would night night hike and get to Terrace Creek at like 2 a.m. Sleep in late and spend the rest of the weekend exploring along the river. We did this quite a few times.
Night hiking the pine ridge trail during a full moon is so amazing, you gotta do that some time!

+1 for Full Moon hikes.

Night hiking is not bad if the trail is more obvious and you have decent lighting and/or good night vision.

I have unusually light colored gray blue eyes and have really good night vision compared to most people i know. There seems to some kind of correlation between pigment in eyes and night vision.

For example, i worked at a school for the blind. There were these famed twins who were albino. Like most folks with this condition, they had some eyesight issues, which is why they were at the school.

However, they had infamous night vision–became the stuff of "legends" and wonderment. Hard to say how much better their night vision was than the average person.

Sorry for the tangent. But yes, i've night hiked before, and probably would have enjoyed it had i had a lot more sleep. I have a hard time sleeping in the day, so i would be more apt to arise early just pre dawn and hike till somewhat late (some night hiking) and still get my good 7 to 8 hrs of sleep.

I kinda like the excuse to get all caught up on sleep and then some. But it does get old waking up at 3am and wondering how you will survive the boredom until morning. Perhaps if you have enough miles to chew up you could simply get on the trail at 4am and enjoy the dawn.

I too had a problem route-finding at night in winter.

In the early 1970's we drove to the Adirondacks relatively late and hiked part of the way by moonlight. Our route was up a wide, well-used trail. But we took a wrong turn at a critical trail junction.

During the summer or during daylight the trail we took would look like a spur trail, off to the side of the main trail. But the spur was well lit by moonlight and the main trail veered off into the dark woods. To us it looked like the spur was the main trail, mainly because the main trail was so dark it looked like a wall of trees.

So we hiked up the wrong mountain, Algonquin instead of Marcy, which was fine because I'd previously been up Marcy in the winter but never up Algonquin (can't say the same for the rest of the group).

+1 on everyone's thoughts on route-finding. I'd summarize my experience as:

Night hiking is great on trails I've been on before. Or that are absolutely can't-miss (e.g. North Rim to River in GCNP).

For new-to-me trails, it is just too easy to miss a turn and it is SO emotionally draining (if you're trying to make miles) to do that unwanted spur TWICE.

Sometimes I've night hiked just get enough hours for the hike. I hike, I don't run, so a 40-mile day takes me 15 hours or so. For 50 or 60 miles in a day, I start and finish in the dark even in summer.

And the solitude is nice. My personal best was 25 miles on a well-developed and maintained trail before I saw another human. Because no one else starts at 4 am. Even on Half Dome, starting at 2 am avoided all other hikers until a few others came up to the top after me, but I had the 9 miles up all to myself.