The period of time when the Solar is no more than six degrees down below the horizon at both dawn or sunset. The horizon must be clearly outlined as well as the brightest stars need to be noticeable less than excellent atmospheric conditions (i.e. no moonlight, or other lights). One https://allkindsofsocial.com/story181347/easy-tips-about-how-to-save-money-with-environmentally-friendly-weather