Not that I care much about Saint's Days and so on, here's a total legend who's worth looking at, who's day is today.
Mike Reeves has some excellent talks on Theology Network.
Athanasius fought and battled the Arians nearly all his life, the Council of Nicea happened fairly early on in his life - he was there as an assistant to his predecessor as Pope (Bishop) of Alexandria. Arianism remained despite being condemned, and Constantine's son and successor as Emperor of the Eastern Empire was an Arian. Athanasius spent a lot of time in exile (firstly for refusing Constantine's demand to install Arius as a deacon in Alexandria!). Athanasius decried that he was against the world - which wasn't too far off, though he had a lot of fans, not least the people of Alexandria.
Athanasius defended the gospel from attacks by showing how Jesus needed to be both fully human and fully God - "of one being with the Father, begotten not made" - otherwise Christianity would make no sense. Without the eternal Son becoming incarnate, Christianity becomes nonsense.
Here's to St Athanasius - a man that held firm to the gospel, when rulers and powers and what seemed like the whole world was against him.