This Saturday, 99% of people on Earth will get sun at the same time

This Saturday, July 8, a majority of the Earth’s population will be able to glimpse the sun’s rays.

Ninety-nine percent of the world’s population, nearly eight billion people, will be able to see at least some sunlight at the same moment. Light will reach a majority of people on Earth for about a minute just after 7 a.m. Eastern Time, but not everyone will experience the same intensity of the sun’s rays. 

People living as far east as Japan will see just a hint of evening light while people living as far west as California may only see faintest glimpses of early morning light—excluding places where the sun is blocked by cloud cover.

North and South America, Europe, Africa, and most of Asia will experience sunlight while Australia, New Zealand, and the Pacific Islands will be in the dark.

A viral moment in time 

Last year, a post on social media showing most of the world in some form of daylight went viral, prompting a fact-checking investigation by Time and Date, a Norway-based website that tracks and calculates temporal phenomena. 

Their research showed that the claim was true—with some caveats. To count 99 percent of the population, all light from the sun counts, even dark twilight. Only around 83 percent of the world will experience “true daylight” when the sun is between dawn and dusk. Sixteen percent of the world will see some version of twilight, including the darkest form of twilight, a time of day when the light outside is nearly indistinguishable from night. 

In cities where light pollution obscurs twilight, residents likely won’t be able to see the faint wisps of the sun.

This phenomenon of sunlight occurs partially because of where the world’s population is concentrated—on land. The portion of Earth that will be in pure night light falls over the Pacific Ocean, an expansive area covering about a third of the globe. Regions experiencing at least some light include the world’s most populated places.

Why does this phenomenon occur? 

This moment of light isn’t as rare as you might think. Time and Date also found that a 60-day window from May to July experiences essentially the same effect, with more than 98 percent of humans on Earth getting some light from the sun for a few minutes. This is due partially to the fact that almost 90 percent of the Earth’s population lives in the Northern Hemisphere, the hemisphere tilted closest to the sun during the northern summer months. 

Notably, the day when the maximum number of people can potentially glimpse sunlight does not fall on the summer solstice, the longest day of the year in the Northern Hemisphere annually, which was on June 21 this year.

(Learn more about the summer solstice.)

While it might seem like the summer solstice should be when the most people see the most sunlight, July 8th’s claim to fame once again owes its status to where people on Earth happen to live.

As Time and Date explained last year, after the solstice, the Earth tilts ever so slightly away from the sun, shortening the average day but exposing populations farther south to more daylight hours.

Wherever you’re experiencing sunlight, follow these tips to protect yourself from the grueling summer heat—and throw some sunglasses on to protect your eyes, and your baby’s.

And if you’re not a summer person, start counting down the days to December 6 when about 85 percent of the world will collectively experience night.