We had to change a class but the individuals calendars don't seem to be updating, can this be fixed?

Summary:

We had to change the date of a class. Individuals had already enrolled but they are saying their calendar is still showing the old date. Is this supposed to update? If so, what do we need to do to insure this happens.

Content (required):

ILT class

Version (include the version you are using, if applicable):

Fusion

Code Snippet (add any code snippets that support your topic, if applicable):