CSV Updates to Date Fields

Question

Using External System Import, I'm trying to run a simple update to a few hundred tickets', date fields Start Date (cf) and the delivered Due Date field.  I'm using a dd-MMM-yyyy format in both the CSV and mapping the importer to the same.  The importer throws no errors or warnings but the fields are not updated.  This IS a capability of the ESI (update) importer, right?

Nick.Ockenfels · Accepted Answer

Thanks but I have resolved this.  It appears to have been an issue with the date format.  I tried several formats with the above being my "goto" (dd-MMM-yyyy).  The successful format was the delivered "mask" provided by the import wizard itself with two extra Ys: (dd/MMM/yyyy).  I had to format the Excel/CSV cells as "Custom" with this same format.