Abstract: Apparatus for adjusting the biological clock of, e.g., an intercontinental or transcontinental airline traveler includes a luminaire disposed adjacent a front edge of a seat pan of a seat. The luminaire is coupled to or includes a light source; preferably the light source is disposed remotely from the luminaire and is coupled to the luminaire by a light guide. The luminaire may have a flexible reflecting element to increase light intensity on the backs of the traveler's knees. Using the luminaire to shine bright light on the backs of the knees of the traveler permits adjustment of the biological clock of the traveler in flight.