You could setup a google calendar and perhaps use a Persistent notification?
The “Persistent notification” notification needs to be acknowledged for it to go away.
But you could also have the calendar event turn a light on somewhere to remind you?
I have an example of using Google Calendar to turn lights on / off depending on what I am working. You can use that as a starter RESOLVED - Google Calendar based lights
Also my GitHub is here
Take a poke around, I need to update it all really as I have not pushed any code updates in 2 months.