The blue hour (from la hora azul in Spanish, or from l'heure bleue in French) is the period of twilight early in the dawn each morning and late in the dusk each evening when the sun is at a significant distance below the horizon and the residual, indirect sunlight takes on a predominantly blue hue. This effect is caused by the relative diffusibility of short blue wavelengths of light versus the longer red wavelengths. During the blue "hour" (typically a period about 40 minutes in length), red light passes straight into space while blue light is scattered in the atmosphere and therefore reaches the earth's surface. Many artists treasure this period because of the quality of the light.
The blue hour is famous for its romantic connotations, particularly in the arts. A colloquial French saying characterises the blue hour as a time of confusion and mystery, since it is impossible to determine whether it is really night or day.
As a result of the perceived specialness of this time, there are various restaurants, theatres and hotels called L'Heure Bleue located worldwide. There is also a women's perfume by Guerlain (1912) of the same name.
In English culture the term was used to describe the period of inactivity and uselessness a drinker encounters when pubs and other licensed premises have closed after the lunch-time session (typically 3:30 pm), but have not yet opened for the evening session (typically 6:30 pm). The blue hour has now been largely abolished in England, Scotland and Wales in favour of all-day opening.
L'Heure Bleue is a concept often expressed, in his works and in his thought, by the contemporary artist Jan FabreThe cover background of The Junior Encyclopedia of Canada, Volume 5 (S-Z)A series of city scenes by David Mamet collected in his Goldberg Street: Short Plays and Monologue anthologyBlue Hour (2003), a book by Carolyn ForchéBlue Noon (2005), the third book in Scott Westerfeld's Midnighters trilogyL'heure Bleue, a book by Edward GoreyThe Blue Hour (1999), a novel by T. Jefferson Parker in the Merci Rayborn seriesThe Blue Hour (2002), a romantic novel by Kate ThompsonThe Blue Hour (1989, reprinted 2012), a novel by J.P. Smith.Blue Nights (2011), a memoir by Joan Didion, which makes frequent reference to the blue hourThe first portion of the 1987 episodic film, 4 aventures de Reinette et Mirabelle, by Éric RohmerA 1993 film Die blaue Stunde by director Marcel GislerThe TV calendar series Jul i Blåfjell (Christmas in Blåfjell) associates magic/other-wordly powers with the Blue Hour - blåtimen, Jul i Blåfjell (Norwegian Wikipedia) (1999)The Blue Hour is a 2007 film starring Alyssa MilanoThe blue hour is also a common theme in popular music and the subject appears in various songs:
Pete Anderson – "Blue Hour"Blank and Jones – "Die Blaue Stunde"Turin Brakes – "Blue Hour"Stephen Cummings – "Blue Hour"Vanessa Daou – "This Blue Hour"Christian Death – "The Blue Hour"Richard Clayderman – "L'Heure Bleue" (composed by Olivier Toussaint)Bent Fabric – "The Blue Hour" (Recording duet with Acker Bilk, also theme from Danish TV variety series hosted by Fabric; composed by him.)Peter Fox – "Schwarz zu Blau" ("Black to Blue")Nina Gordon – "The Blue Hour"Faun (band) – "Blaue Stunde"Françoise Hardy – "L'Heure Bleue"Killer Loop – "The Blue Hour"KLF – "Madrugada Eterna"Ute Lemper – "L'Heure Bleue"John Mackey – "Hymn to a Blue Hour"Madrugada – "Strange Colour Blue"; both the song and the eponymous album title (which means "dawn" in Portuguese and Spanish) refer to the blue hourThe Moody Blues – "Twilight Time"Roy Orbison – "When The Blue Hour Comes"Oysterband – "Lost and Found"Radiohead – "The Gloaming"Klaus Schulze – "Blaue Stunde"Andreas Vollenweider – "Chanson de l'Heure Bleue" ("Song of the Blue Hour")Stanley Turrentine with The Three Sounds – Blue Hour (album)The Platters – "Twilight Time"Lana Del Rey – "Video Games"; contains a line "Kissing in the blue dark..." which can be understood as a reference to blue hourIAMX – "North Star"Joe Jackson – "The Blue Time"