Why is Japan kept in dark?

For tourists and residents alike, the quintessential image of Tokyo is of a city lit by artificial light. As soon as twilight gathers, the central shopping and entertainment districts of Shibuya, Shinjuku and Roppongi are awash with neon, shining from each shop and office, even turning the night to a purplish haze.

This image, in fact, aptly describes any city in Japan, from Sapporo to Naha. Few seem to wonder why the country spends so much time in the dark, whether it is desirable to expend so much energy on illuminating it, or what the alternatives might be.

During the last weekend of this month, throughout the developed world, residents will turn their clocks and watches back by an hour. This will mark the end of a summer characterized by long, light evenings, enabling citizens to work and play by natural light. Of the 30 OECD countries, 27 have opted to introduce daylight-saving time from April to October.