I’ve had various calendar programs. I find the ones for smart phones especially egregious. I hate typing on miniture keyboards. I hate so much, I’m turning in my “smart” phone and getting one that is just a telephone. I think that giving a large number of applications to a phone is a waste of time and courting with danger by putting “all of your eggs in one basket”.
When the phone fails (as it inevitably will) you lose much more than phone service.
I prefer a Daytimer where I can write my thought and appointments immediately. I’ve been using them for twenty years and never had a failure where all my data was lost. I can’t say the same for my computers or smart phones.