How do I amend and increase an employees holiday entitlement?

Hi @Rebecca Bartlett​ 

If 23 days +8 is you standard holiday entitlement, this needs to be updated in the Job titles.

If this is a long service award an increment can be added in the job titles.

This can be done for both Full time and Flexible employees.

This article explains how to update holiday in job titles

https://fc.force.com/customer/s/article/WFM-Creating-a-Job-Title

Hope this helps

Kindest

Debbie