Getting the difference in days between Chosen and Duplicates with Unique ID

Hello

New to KNIME

I am working with Healthcare data

Every patient unique MRN

I am looking at length of time between requests for analysis

I used the duplicate filter to pull out duplicate requests and have them marked as duplicate and chosen (first) in a duplicate column

I need to see the length of time in days between requests from earliest request to next one? Some patients have repeated analysis more than once

Any help gratefully appreciated