Okay, I say we go with shy's days of the week and Draken's seasons proposal, and just keep the calendar to twelve months. Now for month names...

I love the idea of luminosity being the main reason behind seasons, since the temperature is generally just "fucking cold" all the time. :p

Hm, what if we just had two seasons for two halves of the year? The Bright season and the Dark season. Would this work?