My job involves working a few days in one place, and a couple days at another place, sometimes multiple places in the same week, and never any kind of repeat schedule. Work days involve things like making sure I have clean work clothes, and gasoline in the tank, so I need to be able to see what I have coming up.
Call me old fashioned, but I cannot organize my life on any kind of digital calendar. I need an old-school paper calendar with the whole thing visible without clicking or swiping or pinching. And I need it staring me in the face every single day without me having to remember to open it.
I hang my calendar in a very small room that is visited several times a day. And the calendar is the only thing hanging on the wall opposite the only seat in the room (ahem).
This is the best and longest practiced tip that I picked up from Flylady.net: "Hang your calendar in the bathroom."