A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
It worked fine for me in a US English version of Excel (your exact formula). your reference to scandinavian dates might suggest several things.
Is your list separator a comma? Perhaps it should be a semi-colon
The names of your functions may not be the same as the US English version so the function isn't recognized.
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Regards,
Tom Ogilvy