I rely on the calendar function on my phone as I have dyscalculia in addition to migraine brain fog and struggle to remember dates and times.
I also rely on multiple alarms during the day to keep me on schedule as well as prevent myself from over doing it if I am enjoying myself or thinking of pushing through an event. Every two hours my phone chimes to remind me to check in with myself (meals, rest, everyday chores, etc). It's also a handy socially acceptable "out" from a situation. To say "gotta go before I get a migraine" is less acceptable than "gotta go, I have another engagment" when the phone chimes.
I've found the Migraine Buddy app helpful for awareness and tracking of triggers, therapies, and the migraine events.