DST (Daylight Saving Time) is coming up this weekend, where we will be setting our clocks again one hour ahead. This is not a naturally born cycle, but something culturally designed by society, and according to Adam Guren and Emma Lind from the Harvard Crimson the DST should be terminated:
http://www.thecrimson.com/printerfriendly.aspx?ref=520642 [1]

Also, there is now proof that DST in Spring is especially hard on B's.
Read excerpt from below article (link at bottom):

"It may seem obvious, but science has just confirmed that daylight saving time disrupts our body clock, especially if we're late risers.

Dr Till Roenneberg of Ludwig-Maximilians University [2] in Munich, Germany and colleagues report their findings in the journal Current Biology [3].

"Our data indicate that the human circadian system does not adjust to [daylight saving time]," the researchers say.

A quarter of the world's population is subjected to a 1 hour time change twice a year, yet the impact of this change is poorly understood by science.

They found that during standard time, people tended to adjust their wake up time to fit in with the dawn, but this adjustment did not happen during daylight saving time.

Larks and owls

In a separate study, Roenneberg and team looked at 50 people whose natural inclination was to wake up early (larks) or late (owls).

The researchers found that both larks and owls adjusted well to the release from daylight saving time in autumn but had problems adjusting to the imposition of daylight saving time in spring.

This was particularly the case for the late rising owls.

Roennenberg and team say the effects held for weeks, perhaps causing people to feel continually sleep-deprived in the spring and summer."

for more on this, visit:
http://www.abc.net.au/science/news/stories/2007/2070223.htm [4]