Here in the Netherlands we also use daily planners and we plan ahead. This means that we also plan visits to our family members, there are no or almost no unexpected visits. Sometimes someone calls and asks: are you free tonight, then we will ....... But that is an exception. We usually make appointments, sometimes weeks before the actual date. But mostly with our daily planner on your lap, not by heart.
I've been told a few times that life in the Netherlands has a lot of similarities to life in Japan. Based on your description of making plans, I would agree. That sounds exactly how it is in Japan. Sometimes, scheduling a get together can take a week or more because everyone's schedules are so varied. And, yes, spontaneous visits rarely happen here as well. Being American, I miss them.