Daylight Saving Is Only Half the Problem

The other half is our time zones

Sunrise at the winter solstice from my window in Connecticut, 7.28 a.m.

There’s a renewed push to make Daylight Saving Time permanent across the United States. Yesterday, the House of Representatives overwhelmingly passed legislation to keep the clocks from falling backwards come autumn. Much of the coverage focuses on the pluses and minuses of the change. On the plus side, we’d have more daylight in the evening hours in the winter. On the minus side, it would stay dark until mid-morning in some parts of the country. The gain and the cost are presented as completely inseparable.

As CNN put it:

This is a choice between suboptimal options created by how our society functions and how sunlight hours shift over the course of the year because of Earth’s rotation.

Here’s how Senator Tom Cotton put it when similar legislation, which he opposed at least partly because school kids would be going to school in the dark in winter, came up last year:

Not every human problem has a legislative solution. Sometimes we have to live with an uneasy compromise between competing priorities and interests. That’s doubly true when considering how the movement of the stars and the planets affects the lives of 350 million souls spread across our vast continental nation.

The medical profession seems to agree that we should stop changing the clocks back and forth. There’s real evidence that the constant switching causes a kind of society-wide jet lag, with both health and economic harms. But its preferred solution would be to make standard time permanent (and the research backs this up). This, however, presents the opposite trade-off. In parts of the country (including my part, New England) it would get light in the summer at 3:00 a.m. and be dark by around 8:00 p.m. Not great for late baseball games or summer cookouts.

I dislike the clocks changing back and forth as much as anyone. I agree that we should stop springing forward and falling back. But whether you favor setting the clocks an hour ahead or an hour behind, the question of what time it is isn’t a binary choice between keeping or ditching daylight saving. We are not, as Senator Cotton and CNN seem to think, wholly at the mercy of astronomy, with daylight saving the single, imperfect lever available to us as a remedy.

Hiding behind the lever of clock switching is another lever: time zones.

In the United States, ours are too big. About the same amount of longitude separates Boston from San Francisco as separates Boston from Reykjavík, but Boston and San Francisco are only three hours apart, while Boston and Reykjavík are five. Indianapolis is about equidistant from Portland, Maine, and Rapid City, South Dakota. The clocks say the same thing in Indiana and Maine. But in Rapid City they’re fully two hours earlier.

If we fix just the clock switching, in either direction, without also fixing the zones, we will only create an opposite set of undesirable consequences. Make daylight time permanent and the winter sun doesn’t come up until the middle of the morning at the western edge of the time zone. Make standard time permanent and the summer sun comes up at three in the morning at the eastern edge. By all means let’s stop changing the clocks back and forth. But we won’t truly fix the problem until we fix our time zones too.

As I’m writing this, the sun is in a different place in the sky in Hartford than it is in Toledo, which is nearly 600 miles away—but the clocks in both places say exactly 4:10 p.m. Tomorrow, the sun will rise in Toledo nearly 45 minutes later than it will in Hartford. The sun will rise in Chicago less than 20 minutes after that. There’s no astronomical reason that Toledo should be attached to Hartford and not to Chicago. That’s just a decision we have made and a decision we can change. If we redrew the map, maybe Toledo and Chicago could be together, and we wouldn’t have to choose between kids going to school in the dark in Toledo in winter and me being woken up by birdsong at 2:00 a.m. in Hartford in the summer. Whether we choose to make EST or EDT permanent, or whether we keep the current switching system, we need more time zones.

Adding a new time zone or two won’t fix everything. Indeed, the change will come with a whole host of new questions and problems. For example, by virtue of geography, New England probably belongs with the Canadian Maritimes in the Atlantic Time Zone rather than with New York and Washington in the Eastern Time Zone. But are we really going to put an hour between suburban Connecticut and New York City?

But those are human problems, and human problems can have human solutions. The number on the clock is conventional. It bears a relationship to the position of the sun, but it is not a mirror of it the way a sundial is. We decide what time it is. The fault is not in our stars, but in ourselves and the conventions we have chosen. Whatever choice we make about daylight saving, we have drawn our time zones badly.