Fandens fødselsdag refers to two Danish/Norwegian traditional dates: 11 June and 11 December. The phrase originates from older financial terms, where these dates were used for semiannual payments of interest and installments on loans. Today it’s largely a humorous expression noting that the “devil” has two birthdays each year, unlike ordinary people who have one. The term is well- attested in Danish contexts and is often explained in language and cultural sources. Fokuspunkter

• Dates: 11. juni and 11. december [Fandens fødselsdag](javascript:void(0)).
• Etymology: linked to historical semiannual debt payments (terminsbetalinger) on loans and rents.
• Usage: humorous, proverbial, and sometimes found in articles about Danish idioms and language history.

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