Forum:What is one year in GoT?

A year on Earth is 365 days (with their nights) or equivalently, four seasons (spring, summer, autumn and winter). However, in GoT there are nights that have lasted many years and winters that have also lasted many years. Therefore a year in GoT can't be logically defined as a fixed number of days or by the cycle of seasons. How then is a year defined? Mayhaps it has to do with magic.