Ĭivil twilight is the period when enough natural light remains that artificial light in towns and cities is not needed. Midtown Manhattan during civil twilight, demonstrating blue hourĬivil twilight is defined as when the geometric center of the Sun is between 6° below the horizon and the horizon itself. For other uses, see Civil twilight (disambiguation). The collateral adjective for twilight is crepuscular, which may be used to describe the behavior of animals that are most active during this period. For example, very old people may be said to be "in the twilight of their lives". Owing to its distinctive quality, primarily the absence of shadows and the appearance of objects silhouetted against the lit sky, twilight has long been popular with photographers and painters, who often refer to it as the blue hour, after the French expression l'heure bleue.īy analogy with evening twilight, the word twilight is also sometimes used metaphorically, to imply that something is losing strength and approaching its end. When the Sun again reaches 18° below the horizon, nighttime becomes morning twilight. When the Sun reaches 18° below the horizon, the twilight's brightness is nearly zero, and evening twilight becomes nighttime. The lower the Sun is beneath the horizon, the dimmer the twilight (other factors such as atmospheric conditions being equal). The word twilight can also refer to the periods of time when this illumination occurs. Twilight is light produced by sunlight scattering in the upper atmosphere, when the Sun is below the horizon, which illuminates the lower atmosphere and the Earth's surface. Evening twilight: civil, nautical, and astronomical stages at dusk. The apparent disk of the Sun is shown to scale. Morning twilight: astronomical, nautical, and civil stages at dawn. Twilight is the time period between dawn and sunrise, or between sunset and dusk. Leviton Decora Single Pole, Preset 60 Minute, 5 Button Countdown Timer SwitchDecora Single Pole, Preset 60 Minute, 5 Button Countdown Timer Switch.For other uses, see Twilight (disambiguation). Leviton 5-Button Timer Color Change Kit5-Button Timer Color Change Kit for LTBxx Series Preset Countdown Timers. Leviton Decora Preset 2 Hour Countdown TimerDecora Preset 2 Hour Countdown Timer. Leviton Decora Preset 30 Minute Countdown TimerDecora Preset 30 Minute Countdown Timer. Leviton Decora Preset 15 Minute Countdown TimerDecora Preset 15 Minute Countdown Timer. Leviton Decora Vizia 24-Hour Programmable Timer SwitchVizia+ 24 hour Timer 120VAC, 60HZ, 1800W Incandescent, 15A Resistive/Inductive, 1HP, for single pole, 3-way or more locations, with astronomic clock, backlit LCD display, timer settings at a glance, gree. Leviton Decora Preset 12 Hour 5 Button Countdown Timer SwitchDecora Preset 12 Hour 5 Button Countdown Timer has 4 preset buttons for 2, 4, 8, and 12 hours and also a dedicated Off Switch. Leviton Decora Preset 60 Minute 5 Button Countdown Timer SwitchDecora Preset 60 Minute 5 Button Countdown Timer has 4 preset buttons for 10, 20, 30, and 60 minutes and also a dedicated Off Switch. Leviton Trimatron Rotary Lighting and Fan Controlsĭecora Preset 60 Minute 5 Button Countdown Timer Switchĭecora Single Pole, Preset 60 Minute, 5 Button Countdown Timer Switchĭecora Preset 12 Hour 5 Button Countdown Timer Switch.Leviton Decora True Touch Lighting Switches.Leviton Decora Mural Lighting and Fan Controls.Leviton Decora Lighting Occupancy Sensors.Leviton Decora SureSlide Lighting and Fan Controls.Leviton Decora IllumaTech Lighting and Fan Controls.Leviton Decora Timer Switches Decora Programable or Countdown Timer Switches for conference rooms, bathrooms, hot tubs, exhaust fan motors and more. GSA Schedule Contract Number: GS-35F-0419X and Federal CAGE Code: 1WXV7
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