What region are you taking about? When each of the poles are in their winter time, it is always dark. In other regions that isn't the case.
This is not scientifically possible, something would have to be covering, and if it was something like a solar eclipse, those cant happen for that long.
What you've been hearing is a completely false rumor. This whole 15 days of darkness was a old rumor spread around by false prophets and tabloids, they've been doing this type of stuff for years. NASA even addressed the issue saying that these claims are untrue. Basically don't believe everything you hear on the internet, since 12/21/2012 was a complete failure than I guarantee you this will be a failure as well.
Believe the people that said California was going to sink into the ocean, and the ones that said the world would end in 2012 ._.