Oh God, your comment triggered my PTSD… One of my first jobs I worked at, I had to restock, multiple times a day, a bin with a bunch of items that were very delicate and wrapped in super thin & delicate plastic. But the box they came in was made of super heavy duty cardboard. Like this shit was originally intended to be some kind of bullet proofing material but accidentally got used to make boxes. Even worse though was that each open end of the box was glued shut with enough glue to stick the Titanic back together and still have some left over and then stapled.
I hated those boxes.

If you have android you can set different ringtones for different calendars, and you can set up multiple reminders for each event.
I then have different calendars for different categories like appointments, bills, birthdays, work events, and then holidays and vacation days.
If you need something more persistent than that AMdroid let’s you set up alarms that make sure you are awake even after you dismiss it.