How to edit formulas in OBIEE (Dates)?

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Good day and Happy Holidaze!

I'm trying to edit a formula in OBIEE, which are centered around two dates; req creation date and offer accepted date.

What I'm trying to do is edit the formula of "Requisition Cycle Time."  The current formula for Requisition Cycle Time is "number of days between the req creation date and the latest filled date."

I need to edit this formula, so it will instead calculate the days between "req creation date" (object path; Requisition Dates>Req. Creation Date) and "offer accepted date" (object path; Job Submission>Submission Dates>Offer Accepted Date). 

Any help and input would be appreciated.  Have a great day.