You just made my point. If you set aside the same day every week for something special/get out of the house/whatever, how can you forget? For us, and our current schedule, Saturday is our day...we make a point to NOT schedule anything with anyone else. It gives us something to look forward to...so if you keep the day consistent, how can you forget? We also take turns deciding what to do because we used to spend half the day asking each other, "What do you want to do?" That got very frustrating and it was happening because we both wanted the other to be happy...now we take turns. Today is my day to pick and I have chosen to go kayaking, fishing and then to an owl prowl. Next week, he will pick.
Regarding the journal idea, I use my calendar for that. I don't think it's a smart idea to keep a journal and then show it to your wife when she is wanting to go somewhere and you want to show her when and where you just were. Sometimes a girl just wants to do SOMETHING different!
And Gnu, my husband and I have very busy schedules and don't see much of each other during the week, so we don't have the need for a day apart! But hey, whatever works for you, right?