LibreOffice Calc: Tools -> Options | Language Settings -> Languages
Language of:
User interface
Formats:
Locale settings
Default currency
Decimal separator key
Date acceptance patterns
Default Language for Documents:
Western
[] Asian
[] Complex text layout (with the option to set it it for current document only).
Enhanced Language Support
Ignore system input language
TODO
These settings seem to be common to all libre office products. Thus, this page should be moved below development/Software/LibreOffice/GUI/menu/Tools/Options ...