Possible Clues:

• Small heartless woman consuming free evening
• Setter unhappy when all becoming dimmer?
• Newspaper depressed when shining light leaves
• Setting time's free in most quarters
• Evening Standard originally free when unloaded
• Loose woman's first to break up partners at the end of the day
• Shivery nudes beginning to edge away -- now possibly?!
• Students, upset by low grade, now rioting at the end of the day
• Dusk makes mummy's boy, by the sound of it, depressed
• Local star is dejected, when the lights come on