Monday. A new week. I know people who make monthly plans. They know what they're going to do on each day for a whole month. In some places that's nothing unusual. A few years ago I went to Tokyo. I contacted a friend, it was July, and she got back to me with: "Great, let's meet! I'm free in the afternoon on the 14th of November".
Needless to say we didn't meet. However, I try to make weekly plans and if something comes up for a later date I'll keep it in mind or take a note. One week is plenty to organize, and to me it's simpler, because weeks have a pattern. Work at the shop from Tuesday to Thursday, skate on Friday, meet the guys on Saturday, play football on Sunday.
Other work and dates with my lady are fundamentally placed underneath all that, so things can change at any time, but there is other stuff that comes up unannounced and throws everything out of order. Sometimes that's a good thing, but for a person who doesn't like surprises they're mostly bad news. Sometimes I think I'm getting old. Sometimes.