Trying to find matching serial numbers, then use delivery date of the first entry to derive support date of 2nd entry. The below works for the initial entry but the Extension Order gets #Invalid Data Type error. Thank you in advance for your suggestions.
=IF([Order Type]@row = "New HW", DATE(YEAR([Delivered Date]@row ) + VALUE([Years of Support Purchased]@row ), MONTH([Delivered Date]@row ), DAY([Delivered Date]@row )), IF([Order Type]@row = "Extension Order", DATE(YEAR([Delivered Date]@row ) + VALUE([Years of Support Purchased]@row ), MONTH([Delivered Date]@row ), DAY([Delivered Date]@row )), ""))