The equinox came and went on a Wednesday. Since then the nights have been longer than the days, and they will keep getting longer until shortly before Christmas.

You may have noticed it in the way waking has gone heavier, or in a four o’clock that arrives already dim.

The Chinese calendar has a name for the fortnight we are standing in, and the name is the useful part.

It is called Qiufen. The second character means division, and the term does two jobs. It marks the point where day and night are equal, and it sits at the middle of autumn in that system, which began in August and ends in early November. The year is not turning towards autumn. It is halfway through.

After Qiufen, the dark has the majority. That is the fact underneath October, and every tradition that built a festival of lights in the coming weeks was answering it.

Here is why it matters more for you than for most people. Almost every rhythm in the body is set by light. Not by willpower, but by light arriving at the eye in the morning and telling a small structure in the brain what time it is. That signal sets sleep, alertness, hormone timing and much of mood.

And the light is disappearing faster now than at any other point in the year. Day length does not fall evenly. It changes fastest around the equinoxes, so at temperate latitudes you are losing several minutes of daylight a day right now. The change you are feeling is not gradual. You are standing in the steepest part of the slope.

Which explains something you may have filed as a failing. If your sleep has slipped, if mornings have become harder over the last fortnight, if the afternoon drop has moved earlier, that is a system responding to a fast change in its main input. It is not a lack of discipline in September.

Two things plainly. Seasonal depression is a recognised condition with treatments that work, including light therapy, talking therapy and medication, and if this happens every autumn it is worth a conversation now rather than in December. And if the drop has gone beyond heaviness into not wanting to be here, that is a call to your doctor or a crisis line today, not a seasonal note.

For the ordinary version, the answer is boring and it is mostly about mornings:

Today’s Practice

Morning light, cheaply. None of this requires equipment, and outdoor light on a grey day still beats anything indoors.

On a hard day, open the curtains before anything else and sit where the light falls. And if getting outside is not possible for weeks at a time, say that to your doctor rather than working around it privately. There are options, and they start with someone knowing.

What the Research Says

Light therapy for seasonal depression has a reasonable evidence base, which is not the same as a settled one. Trials generally find bright morning light helps, and several guidelines list it as a first line option. The awkward part is blinding, because nobody can hand you a convincing fake light box, so placebo is hard to separate out. Researchers have tried dim red light or ion generators as controls, with mixed success. What survives is that morning timing matters, that brightness matters, and that the effect appears within weeks. It is one of the better supported non drug options here.

Everyone’s Talking About

Sunrise alarm clocks are having their annual moment. The idea is sound: a light that brightens gradually before you wake, mimicking a dawn that has not happened yet in October. Small trials suggest dawn simulation helps with waking and with seasonal low mood, and a few found it comparable to a light box. The studies are small, the devices vary in how bright they get, and many are dimmer than the ones used in research. As a way to make winter mornings less brutal it is reasonable. As a treatment for a diagnosed condition it is not the same thing.

From the Old World

Icelandic has a word for the season rather than the weather. Skammdegi, the short days, names the stretch when daylight collapses to a few hours and the whole country lives inside it. What interests me is that it is a noun. Not a complaint, not a mood, a period of time with a name, the way we would say spring. A culture that far north treats the dark half as a thing you are inside rather than a thing going wrong with you. There is no equivalent in English, which is why we reach for personal explanations instead.

Come Home

Five lines for the steep part of the slope.

One act for today, if you want one. Get outside for ten minutes before mid morning, or sit at the window with your first cup of the day.

The nights took the majority last week. You did not do anything wrong, and neither did October.

P.S. Tomorrow, sixty seconds, and all of it happens at the window. One minute of light, and the smallest possible version of everything in this issue.