GREP style as part of paragraph style

Question

I'm wanting to create a GREP style that uses a character style. Whenever certain words (No class) appear followed by dates. Sometimes it is a single date and sometimes more than one date. For example:
No class 7/11.
No class 7/11-8/11.
What I have so far is:
No class \d+.
This works okay through the words "No class" and the first digit, but not for the whole sentence. I've tried different combinations but nothing that works correctly.
Can anyone help?

Answer 1

Peter,
I so much appreciate your help with this. Your explanation makes it understandable. But there is still a mystery.
The GREP for Instructor: Instructor Name works fine. The GREP for the date sentence is not working. Instead of the date sentence becoming italic, it  matches the first part of the paragraph. This is what the GREP looks like:
This is what the paragraph looks like with the GREP applied:
It should look like this:
In a separate issue in another paragraph, which is a heading paragraph, I have a similar situation. The headings are bold, some headings list ages, and some list ages AND whether parental participation is required. I thought I could extrapolate from the information you've given me to fix this paragraph as well. I've tried different combinations, but so far haven't gotten it to work. The paragraph looks like this:
But it needs to look like this (bold paragraph with ages in regular,and parent requirement in italic):
The heading doesn't always have an age requirement, and doesn't always require parental participation.
The catalog is quite long, so if there is a way to fix these two types of paragraphs, it would save a ton of time.