I use Notion+Notion Calendar for this and I delegate to it a lot of stuff: bureaucracy, booking the barber, changing the bedsheets, all my work, birthdays, etc etc. How can people trust their brain with more than two or three items is unfathomable to me. I mean, when I was younger I could keep in mind a dozens upcoming appointments and go through them every few hours to make sure I wouldn’t miss anything, but as soon as your routine is disturbed by work stuff, it’s impossible.