Days between Step/Status

Summary

OBI Days between Step/Status

Content

I am trying to create a custom calculations to show the number of days a submission remains in a particular step and status. I've tried using the TIMESTAMPDIFF but it doesn't seem to work with CASE WHEN to specify the step and status. Any ideas of what I am doing wrong? Here is an example of the formula

TIMESTAMPDIFF (SQL_TSI_DAY, (CASE WHEN("Submission CSW Status - Historical"."Historical Step Name" = 'Recruiter Review') AND ("Submission CSW Status - Historical"."Historical Status Name" = 'To Be Reviewed') THEN Max("Submission CSW Status - Historical"."Submission Historical Status End Date") END),CASE WHEN("Submission CSW Status - Historical"."Historical Step Name" = 'Recruiter Review') AND ("Submission CSW Status - Historical"."Historical Status Name" = 'Reviewed') THEN Max("Submission CSW Status - Historical"."Submission Historical Status End Date") END)