No, not the book by Friedrich Nietzsche. Although Nietzsche's work has much to recommend. Sadly, his malevolent sister Elisabeth twisted his words and works to further her own later nasty anti-semitic and pro-Nazi projects. Much maligned, usually by people who have never read him, Nietzsche doesn't deserve such a reputation.
Anyway, maybe that heading should read: Twilight of the Idles. (There is a great essay by Bertrand Russell titled In Praise of Idleness. But I digress.)
Twilight... what is twilight? Anyone read Tristes Tropiques by Claude Levi-Strauss? I remember he spent two-and-half pages analyzing why witnessing sunset and twilight had a different impact on the human psyche than witnessing dawn and sunrise. A fascinating man, a fascinating book. But I no longer have the book to hand.
What is instantly available is a no-nonsense definition of twilight by Hong Kong Observatory. The Obs has also come to the rescue as concerns those bright lights seen in the western sky in late July at the hour crépuscule (Astronomie: lumière du soir). Yes, stargazers: Night Sky in Hong Kong, July to September 2005.