# File lib/spreadsheet/excel/writer/workbook.rb, line 628 def write_workbook workbook, io unless workbook.is_a?(Excel::Workbook) && workbook.io @date_base = Date.new 1899, 12, 31 write_from_scratch workbook, io else @date_base = workbook.date_base if workbook.changes.empty? super else write_changes workbook, io end end ensure cleanup workbook end