we've got a custom date column field on line items of invoices. i'd like to do a summary saved search custom field which somehow indicates whether the values on the line are all identical or if there's a difference between them... the client wants to use a header-level field if all the line item dates are identical. it's for use on a PDF so if it can be some consistent value to indicate true/false of all the line items being equal, that would work fine (if true, just grab the date from line 0). or if i can just get a formula that indicates the "distance" between the largest/smallest dates (which would be 0 if they are the same) that would work too.. just not skilled enough at formulas to know if this is even possible.

yeah its possible - it would be easier through a script