Sleeping early vs late?

I always wondered about this but never really found a proper answer. I know that it's good to get at least 8 hours of sleep, because the REM periods get longer as time goes by, but what about going to bed/waking up time? For example sleeping from 12 am to 10 am vs sleeping from 10 pm to 8 am, which one would be better for lucidity?
I was reading through an article about LDing mistakes, one of them is:

Quote:

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Mistake #2 – Not Sleeping Right

Sleep is of course essential for Lucid Dreams. If you’re not sleeping right, which means comfortably, and while maintaining a healthy sleep cycle, then the chances are your overall health as well as your dreams will suffer.

Without going too much into detail, the natural sleep cycle relies heavily on light and darkness. The body naturally gets into the rhythm of feeling tried when it gets dark and waking up when the sun rises. It’s more complicated than that, but the basic thing to remember is to get up before 9. This will solve almost all the problems, if you get up before 9 every day after a few days any bad habits or only feeling tired at 2 in the morning will be corrected and you’ll naturally want to sleep at about 10-11pm.

This is good for dreams for a whole load of reasons, but the thing to remember here is that it will correct your sleep patterns, and you’ll be able to experience more/higher quality Lucid Dreams.

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It makes sense that sleeping early makes for a good schedule, it's natural to feel sleepy when the sun sets and wake when it rises, at least relatively, right? On the other hand, when I read ETWOLD, I remember a passage from a study that said that many people tend to become lucid in the late morning. ..How are we supposed to sleep for the best chance of lucidty?

I think the real goal is to get a good night's sleep -- or rather be in the process of a good night's sleep -- before you begin LD'ing; when that "night" occurs may not be terribly important. The article you posted seems to be talking about sleep in general, which is fine, but it doesn't include the modifications which might interest LD'ers, with the major modification being tacking a couple extra hours' sleep, possibly with WBTB inserted, to the end of your sleep cycle. The EWOLD guys would call that extra sleep "late in the morning," I would think, which is more a nod toward sleeping later than you normally would sleep, rather than a literal accounting of where the sun might be.

Also, yes, though light is the enemy of sleep, thanks to things like curtains and sleep masks we are no longer a slave to light, and no longer need to wake up at dawn -- just as most of us no longer need to go to sleep (or even feel sleepy) when the sun sets, because we can just turn on a light. So I believe that you start your good night's sleep at pretty much any hour of the night that works for you and that doesn't interfere with your personal circadian rhythm.

On a personal note, my best LD'ing "nights" start with a bedtime of about 3am, a WBTB from 8-8:30, and sleep until around noon (much later when the dreams go well). I think that a good night's sleep is much more related to a person's specific needs and habits than it is to the height of the sun.