Why do we still change our clocks in Autumn and Spring?

In the 19th century, the railroad connected people across distances so great that time zones needed to be implemented to align rail schedules. In the 20th century, the aeroplane eliminated all time zones, at least for pilots and airport personnel. Time is about coordination.

Some people think that daylight saving time (DST) nowadays does more harm than good. A state commission in Massachusetts has recommended that the state move its official time zone from Eastern to Atlantic Time and do away entirely with the back and forth of daylight saving. The move would give Massachusetts more daylight in the evenings – currently, winter sunsets start as early as 4.11 pm.

The original idea was to reduce energy use by providing more sunlight in the summer mornings. Savings in electricity costs and stress on the electric grid have been cited as reasons for changing clocks between summer and winter. But since energy demand actually peaks in the early afternoon in winter, longer evenings would actually reduce the need for artificial lighting. A 2008 report by the Department of Energy found that in 2005, when the US extended summer hours for a few more weeks into autumn, electricity use decreased by a small amount.

The Massachusetts commission, concerned about children waiting for school buses in the dark, also recommends delaying school start times, resulting in a better alignment with adolescent sleep patterns, driven by hormones. Later school start times also result in higher test scores and fewer teen car accidents.

If Massachusetts acts alone on this, it could cause a certain amount of chaos, so the commission recommends that the state should only make this move if a majority of other north-east states join in.

Seems sensible. But Steve Hanke, a professor of applied economics at Johns Hopkins University in Baltimore, suggests we use one universal 24-hour clock, followed by everyone on the globe. Pilots and stock exchanges use it already. This would mean that in some places, the sun would rise at, say, noon, instead of 7 am. It works in China, which has one official time zone for the entire country, despite covering five time zones geographically. Local custom dictates at which hour work begins and ends. Hanke thinks it’s only a matter of time before this practice is adopted globally, and our increasing reliance on technology may lead us there. (based on an article in New Scientist by Chelsea Whyte).

I’m not at all sure about one universal 24-hour clock, and what the advantage would be. Surely light, and the movement of the sun around the planet, has to be taken into account? I am writing this at 17.45 Eastern time,and it is dark outside. Being told that, after all, it is 13.45 would be a stretch for me at my age. I suppose one could get used to it, but I wonder how long it would take for 7 billion people? Could someone ”enlighten” me?