Calendar doesn't work for me and since my ADHD diagnoses I know why -- I need a constant rotating set of micro and macro lists to barely keep some perspective of more than 2 days from now and get shit done. Moving everything to a calendar immediately becomes background ignore noise for me and it's even worse because it comes from that bothersome box the phone
The best system I have, as someone with ADHD, is keeping a notebook with a handwritten todo list. All I have to do in a week is make sure to finish the todos I write down. That’s it. I use the calendar for meetings and things I want my phone to remind me about, but most everything is in a handwritten todo list that I keep visible on my desk at all times.
It seems to strike a balance between being flexible and letting me roll with things as they come at me, while also keeping my list of things to do at a manageable level so that I'm not distracted by stuff far in the future and not feeling like I'm not making any progress on things.
1. https://www.moleskine.com/en-ca/shop/planners/daily-planner/...