Holiday Entitlement Pro Rata

Holiday Entitlement for employees that do not work a standard 5 day work pattern should be pro-rata accordingly when an employee starts or leaves employment or has a change in contracted days. As the system can automate pro-rata for other areas, I would have thought this would as well. Having just started implementing Staffology, I now have to go and check and / or adjust over 100 clients which is not ideal and very time consuming.