step. 1. create new spreadsheet. 2. change locale to English and date acceptance to d/m/y. 3. enter date 15/11/2012. 4. create new spreadsheet in excel 2007 thai. 5. set calendar type to western. 6. enter date 30/11/2012. 7. copy date from excel and paste to other cell in Calc. 8. date in Cale as 15/11/2012 change to 13/11/2012.
User error, so INVALID! @Rungsan: In reality you only copy numbers instead of Dates. You can see that if you change cell format from date to number in cell. Shown date depends on setting in menu 'Tools -> Options -> Calc -> Calculate - Date' an somewhere in Excel. It is user's responsibility to make sure that both documents use same date base. *** This bug has been marked as a duplicate of bug 37501 ***