How to change date display in Publisher field on KLC

Hi

I have a KLC and would like to change the display of the published date format in the book details page to yyyy from ddmmyy as it is currently.

I have tried to create a custom column with a date format that I can specify is yyyy.

I've then tried to create a metaboard plugin with this template program: raw_list('publicationdate') bit I keep receiving an error message on the book details page plus the previous date format is still there. Ive attached a screenshot of the error message.

Would greatly appreciate any help at all. Thank you