Google Calendar allows you to set different alert intervals for upcoming events, but this may not be enough for some, especially if the event is early in the morning and you want to sleep.
What to do
In this case, you can use the OnTime Android application, which will help you automatically create appointment alarms from your Google Calendar.
How it all works
The first time you launch OnTime, you will need to grant access to data from the Calendar, as well as allow it to work in the background. Then, select one or more calendars and set the default time for how many minutes before the alarm should go off.
All these settings can be changed in the future if necessary. Otherwise, almost nothing more is required of you.
After a while, the events from the calendar will appear in the list of alarms inside the application, with a switch to activate the alarm. Yes, the process is not entirely automatic.
By default, the alarm will be activated according to the settings, but you can easily change it to any interval convenient for you.
You can try OnTime for free for a month, and then you will have to pay a one-time fee.