# File lib/spreadsheet/excel/writer/workbook.rb, line 245 def write_datemode workbook, writer mode = @date_base.year == 1899 ? 0x00 : 0x01 data = [ mode, # 0 = Base date is 1899-Dec-31 # (the cell value 1 represents 1900-Jan-01) # 1 = Base date is 1904-Jan-01 # (the cell value 1 represents 1904-Jan-02) ] write_op writer, 0x0022, data.pack('v') end