Bruce thanks for your help at Thursday's webinar.
Problem with date format when export to Libre Office rather then Excel.
Export works OK except the date format.
Solution
Add 'T0' to the end of the date field.
XML field type is set to 'DateTime' but the time part is not set in the export. So adding 'T0' sets the time to zero. Date now works OK.
Added to xCell.SetCell Procedure in xFiles.clw
If self.workbook.WorksheetQueue.Table.RowQueue.Cells.type = 'DateTime' and p_Data<>''
self.workbook.WorksheetQueue.Table.RowQueue.Cells.data = left(p_Data)&'T0'
End