The sun sets behind Mount Fuji as seen from Tokyo’s Jingu Gaien district, where the new National Stadium for the Summer Games is being constructed. (Photo by Tomoki Mera)

The 2020 Olympic Games in Tokyo are due to take place in the rice-cooker heat and humidity of late July and early August. With the mercury topping 39C this year, the risk to athletes is obvious. Marathon runners dropping like flies would not be a good look for this much-anticipated demonstration of Japanese soft power.

In 1964, the Tokyo Olympics were held in temperate October. The schedules of multi-billion dollar televised sports — such as the English Premier League — now make that impossible. Instead, a partial fix has been proposed in the form of daylight saving time, which would advance Japan’s clocks by either one or two hours, allowing for events to take place earlier in the day. Yoshiro Mori, president of the Organizing Committee for the Olympics and a former prime minister, recently recommended the idea to Prime Minister Shinzo Abe.

At first sight, the prospect appears attractive. In midsummer the sun rises in Tokyo at 4:30 a.m. and sets at 7 p.m. By the time the working day starts, the heat is punishing and sweat glands are in overdrive. Surely there has to be a better way. After all, of the 36 members of the Organization for Economic Cooperation and Development, a club of mainly rich countries, only four — Japan, South Korea, Turkey and Iceland — have not implemented DST, sometimes known as summer time.

But putting the clock forward is no simple matter. DST has been highly political from the start, when Germany, Britain and the U.S. implemented it during World War I. As noted by Vanessa Ogle, a scholar who has written extensively on global time reform, DST was originally promoted in Britain “as a way to curb unhealthy behavior such as rising…