Fast Formula for Length Service in an Eligibility Profile

Summary:

I am wondering if anyone has ever created a fast formula for length of service in an eligibility profile?

For checklists/journeys, the standard length of service used to create an eligibility profile does not work, it requires a fast formula.

Content (required):

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

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