Looking for: Change notes on specific times

[Gurkenbaum]

I tend to forget where or when my next classes are, so I thought about writing all of them into a note that shows up on my rainmeter, but I just want to see the next class. Pretty much notes changing on time.
For example: It's 11.30am, and my next class is at 3pm. The note shown on rainmeter should just show the current class (so I know when it ends), but something like 5 minutes prior to the end, it should automatically show the next class with time and location.
Is there any way to do this, or is there already a plugin that does this?

I started using rainmeter like an hour ago, so I'm completely new to this.

Thanks in advance guys.