I have always been in the habit of washing my clothes early in the morning. Washing clothes at night has never appealed to me. If I wash them in the morning, then they have the whole day to dry, so that by nighttime I can bring them in. Basically there is nothing wrong with washing at night, but it is just something that I am not accustomed to doing. I also think night time is more a time for relaxing than for doing chores and that may be one of the reasons why I never plan my washing at night.