can siri give me reminders of appointments on my calender

Siri can announce your notifications with iOS15. Here's how to set it up:

1. go to settings>notifications>announce notifications
2. toggle calendar to "on"

You can also ask Siri about your upcoming appointments by saying "Hey Siri, what are my upcoming appointment?"

Note that Siri will only read out notifications without you saying "Hey, Siri..." if you are using supported headsets or CarPlay.