> This is especially true for those who reside on the outermost edge of the twilight zones, within the darkest twilight phase called astronomical twilight. Here, the Sun is 12-18 degrees below the horizon. At that angle, the indirect sunlight becomes so thin that it is usually indiscernible to the naked eye.
The article suggests 83% to 90% (not 99%) of people will find it to be light out (daylight or civil twilight) ... not including Californians.
(1) If astronomical twilight and other indirect sunlight counts, then moonlight counts doubly so!
(2) If indirect and thus spatially separated sunlight counts, then temporally removed sunlight, in the form of airglow, should count as well!
Given that, the caviet of direct and indirect sunlight is a huge factor not quantified.