I miss some reminders on my phone, either due to notification fatigue or because I'm away. But some events/reminders I want to be absolutely sure I do - like pay a bill. I want a way to get google calendar to remind me of an event with something like an alarm - the notification sound doesn't turn off until I turn it off. But I don't want to do this for all reminders, only ones I deem important enough.
I found a way to do this - you can use Clara's answer to a similar question to set a long notification sound. In order to make this longer notification specific for certain important events, I noticed that in google calendar/settings/general, there are separate notification settings for calendar notifications and task notifications. I set the task notification to have a long notification sound.