For bonus points, on the management/sales side: - convince a culture with a different week size to adopt the 7 days week. - convince a culture without the concept of calendar to adopt a 10 days week calendar (or 5 day, for the impatient), and then apply previous step.

Ask them for a problem, and solve it in front of the interviewer. If the interviewer doesn't praise your idea, don't even consider applying for such a company.