I mean, in the day and age where you can earn a living, pay bills, purchase groceries and other household items, and have meaningful relationships, all without setting a foot out of the door of your own home and on whatever schedule you prefer, is there really any reason to follow a certain circadian cycle?
On the other hand, if you're upset with where your daily cycle falls out of habit or preference, what really is to blame? There are such modern wonders as alarm clocks, caffeine, and loud music to keep one's self awake during the hours you prefer, and warm milk, sleeping aids, and Yanni for when you're finally ready to succumb to sleep.
So to all my friends who have issues sleeping at night and being awake during the day, I say turn up Funk 49, grab yourself a Coca-Cola or coffee, and enjoy the freedom to sleep when you're tired, and not when you're not. Trust me, the whole up-at-7-for-16-hours thing is overrated.
(And if you're sleeping through things you have to do and not caring enough to buy a cola or an alarm, then I'd say it's time to seek professional medical and/or psychological help.)