Some routers & modems work best with port forwarding if you have a static local IP. Manually set your network interface card (NIC) to use a static ip address. You can also download my FREE Simple Static IP tool to set it for you.
Today is October 14, 2015 so that means that 180 days before today would be April 17, 2015.
So, when we have to define something that occurs before our referance (0) we have to make use of the system in reverse order. Suppose a person 'X' was born 50 years before christ he will get a -50 on the number system. That's 50 BC for YOU. Someone born today will have the year 2014 printed on their birth certificate.