I am using Fantastical. I really dislike the annual subscription model, but Fantastical does the job that Apple doesn't seem to want to do, and does it better. Is anyone using Calalarm? A cursory look at it indicates you can set your own snooze time rather than choose from a list. And as far as I can tell you can buy it, and only pay for updates. But if you choose not to update you do not pay again.
If you're using it, do you like it? AND, if you choose not to update through three or four updates, do you just pay for the most current update if you wish to update on, for example, the fifth update?