In the folklore of Scandinavia, Tycho Brahe days (Danish: Tycho Brahes-dage; Norwegian: Tycho Brahedager; Swedish: Tycho Brahe-dagar) are days judged to be especially unlucky, especially for magical work, and important business transactions (and personal events). Tycho Brahe (1546–1601) was a Danish astronomer, astrologer,[1] and alchemist and as such achieved some acclaim in popular folklore as a sage and magician.