Seasons: how long is your spring, summer, fall and winter?

My game is set for 28 days seasons, all of them. I love all seasons equally and the long length gives me enough time to enjoy them properly. When I used to play with 7 days seasons it felt like the game was on fast forward. I also play with aging off, so long seasons are more suitable for this. I have added a lot of season specific holidays and now the game feels more realistically paced and not like nature on steroids.