As I understand it, a character progresses through an entire life of between 80 and 120 years in one real life year. So about 100 years of character life pass in 1 year, which is roughly a year every 4 days. But time passes differently in-game. In short, you won't have to worry about single-day seasons. There's a good discussion of the topic here: https://chroniclesofelyria.com/forum/topic/837/The-Length-of-a-Day.