Shouldn't I Have a Secretary?

I think I need a secretary. How else am I supposed to remember where I need to be? and evernmore than that, when?

Surely, there must be some kind of concept where days are diliniated on paper, or maybe on a computer. You could write under the heading of the particular day where and when things need to be done, and then you could find out, with one look, where you need to be... Whoever designs that would make a mint.