Traveling across the world and turning your biological clock essentially upside down can definitely cause problems with sleep, both while you are away and when you return.

CNN: Can melatonin prevent jet lag?

Darren Spedale, 38, the website's founder, says he started the company in 2012 after realizing his own biological clock was ticking but he didn't have someone with whom to raise a child.

WSJ: Tech's Over-Sharing Economy

Darren Spedale, 38, the website's founder, says he started the company this year after realizing his own biological clock was ticking but he didn't have someone with whom to raise a child.

WSJ: Tech's Over-Sharing Economy

The research team took fruit flies and removed several genes that regulate their internal biological clock, which, in humans, decides when we wake up and go to sleep.

BBC: Body clock link to cocaine addiction

Lead researcher Professor Dolores Malaspina, of the Columbia University College of Physicians and Surgeons, said her findings showed "a man has a biological clock too".

BBC: 'Older fathers' link to schizophrenia