Sleep studies take place all the time. Pharmaceutical companies, universities, the military and just about every important institution has put in time and money to figure out how people best recharge their batteries. But no matter from what angle researchers examine the science of sleep, the results are always the same. Of all the variables to a healthy lifestyle - diet, exercise, and a good night's rest - the latter is proven time and again to be the most crucial factor in day-to-day wellbeing (and it's worth suggesting that it's the easiest to achieve).
Sleep is a hot commodity. If he's lucky, a typical human being will sleep for about a third of his total life, using that time to rebuild and reinforce the processes that take place during the other two-thirds.
The science of sleep is compelling enough that entire journals are dedicated to sleep studies alone. Cognitive development and memory acuity, two cornerstones of neuroscience, are deeply founded in general sleeping habits. There's even a National Sleep Foundation dedicated to spreading awareness that sleep is this great new thing everyone should try - "It'll cure cancer! Make you more attractive to the opposite sex! Or the same sex!" That's not an exact quote, but it's essentially what they're going for.
College students are notorious for bad sleeping habits, which is somewhat ironic, because party time always takes precedence over sleep, no exceptions; but we dread and lament the insufferable all-nighters as if staying up a full 24-hours to study is a brush with death itself.
And, in a sense, it is. More than one study has proven that sleep deprivation has direct effects on receptiveness, retention, concentration and overall mood. However, the conclusions always fall on deaf ears, as students ever continue to madly cram on eves of exams. Were always sure of ourselves that shorter intervals between studying and testing will directly correlate to better performance.
In every single case, though, researchers have found the opposite. Physiologically, sleep is a passive process, but the neurology of the brain uses sleep as an opportunity to archive information acquired during the waking hours. Sleep expert Matthew Walker, who held an open forum on the nature of sleep for an episode of NOVA, said the architecture of the brain works by processing information at the conscious level while we are learning (something that can only happen while awake and actively engaged). "Sleep then enhances individual pieces of information, and builds associative links between them."
Point being, you can cram all you want, but your brain's neurology physically requires sleep in order to transfer information from your short-term neural pathways into your long-term memory network.
As far as picking times to catch up, there's no universal standard for the proper sleep schedule. In fact, there are lots of professions that almost necessitate expanded sleeping and waking hours. If you do a little research you can find lots of techniques to achieving specialized circadian rhythms with little side effects. Something interesting to note is that spelunkers, if they spend up to weeks at a time underground without time-keeping instruments, will naturally begin to stretch their sleep-wake time, i.e. staying naturally active for longer hours and thus sleeping for longer hours, but not physically noticing any effects.
There isn't a natural constant for determining how we sleep, except the combination of established working hours and 24-hour geological days. If the earth suddenly started revolving slower on its axis (assuming we didn't all die from something else, which we probably would) we would, within reason, be perfectly capable of adapting to longer days. In that sense, the typical college student is ahead of the evolutionary curve on progressive sleep patterns. Go ahead and feel proud of yourself for that one.
As well, the idea that the hours you sleep before midnight are doubly important is a bit of a misnomer. The relationship is somewhat complex, accounting for many unknowns, but the suggestion is only to illustrate that the first couple of hours are the most crucial. The biggest factor to a sound sleeping experience is committing to a relatively stable schedule, and insuring that the sleep you get is of good quality.
So, the moral of the story is, study all day and party all night, but do find some time to recharge. Again, quality is more important than quantity (though a natural rhythm helps). If you do a bit of research, you can find ample ways to specialize your own personal sleep schedule with little sacrifice.
As with all things, you don't have to do it too terribly often, just do it well.