Have you caught yourself on a summer night asking how it could still be light out at 9:30 p.m?
A math blogger and Google engineer who was vexed by this late-light impact on social habits created a map showing how some times zones are awkwardly disjointed with the true solar hour.
Stefano Maggiolo created the map after being inspired by a trip to Spain, but wondering why Spaniards ate dinner so late. “The first night I dined almost alone in a restaurant at 8pm, going away just as people were starting to come in. Of course this can be mostly explained by cultural reasons, but the clearly later-than-usual summer sunsets must also have played a role in shaping the Spanish days,” Maggiolo said in his blog.
This checks for anyone who has lived in different time zones; summer nights in Northern Kentucky seem to go on for hours longer than they “should”; civil twilight stretches out past 9:30 p.m. at times, with late the June sun setting after 9 p.m. By contrast, families enjoying a summer vacation along the U.S. East Coast see their daylight end much earlier; the Outer Banks’ latest sunset of the year is June 26 at 8:22 p.m.
For whatever reason, more of the world seems to be a little bit like Spain—the sun rises and sets later in the day than it should—than the other way around. The “late” places are shown in red, the “early” places in green. The deeper the shade, the more off the time is.
Not surprisingly, Western China is the deepest red. All of China’s clocks are set to Beijing time, meaning that solar noon happens at about 3 p.m. in the far-western Xinjiang province. In defiance of the government, many members of the region’s Uighur minority observe their own time.
Click here to visit Maggiolo’s full resolution map, and see where your time zone and where it falls in relation to the real solar hour.
Follow Elizabeth Kreft (@elizabethakreft) on Twitter.