blissful, you're absolutely right. I didn't think of a "diary" in those terms. I thought only of personal thoughts type of diary.
I actually kept a calender with large day blocks and wrote in the meals I prepared. For almost 2 years. It was quite helpful. Stopped for some reason and now I don't "cook" enuf to start it up again.
I sometimes make notes of cooking in my regular calendar that I keep for appointments, etc. When someone comes to visit. Something extra with the Grands, things like that. So I guess that could be called a diary.
My son (and others I know) keep everything on their phone calenders. I do for appointments, as it will send me timely 'reminders', but with my wall cal. (usually from the pharmacy or grocers - free!) I will sometimes 'go back' and fill in something special that has happened.
I also find the wall cal. much easier to look things up - you can see one month, plus what all that is written, in one glance. Phone's are limited in space for just glancing so scrolling thru takes much longer to find something.