Section 5 of the Federal Trade Commission Act at 15 U.S.C. § 45 Declares Unlawful Unfair or Deceptive Acts or Practices in or Affecting Commerce, the Word Equinox Is Formed From the Latin Aequus Meaning Equal and Nox Meaning Night, the September Equinox of 2026 Occurs at 00:05 Coordinated Universal Time on September 23, Which Is 5:05 PM Pacific Daylight Time on September 22, on That Date the Day Exceeds the Night by Approximately Fourteen Minutes at the Equator, Approximately Eight Minutes at Mid-Temperate Latitudes, and a Full Twenty-Four Hours at the South Pole Where No Night Occurs at All, Sunrise Is Defined as the Moment the Sun’s Upper Limb Appears Though Its Center Is Fifty Arcminutes Below the Geometric Horizon, the Sunset Tables Every Almanac Publishes Assume Thirty-Four Arcminutes of Atmospheric Refraction and a Sixteen-Arcminute Solar Semidiameter, the Date of Actually Equal Day and Night, the Equilux, Falls Several Days Later and Within Two Degrees of the Equator Never Falls at All, and the Product Sold to the Public Under the Name Equal Night Has Contained No Equal Night for as Long as Anyone Has Been Selling It

I. The Prohibition

Section 5 of the Federal Trade Commission Act, at 15 U.S.C. § 45(a)(1), provides: “Unfair methods of competition in or affecting commerce, and unfair or deceptive acts or practices in or affecting commerce, are hereby declared unlawful.”¹

The provision is categorical. It contains no exception for representations made in Latin. It contains no exception for representations made in almanacs, wall calendars, or the evening weather segment. It contains no exception for a representation that has been repeated, without correction, for approximately seven hundred years.

Under the Commission’s long-standing deception framework, a practice is deceptive when there is a representation, omission, or practice that is likely to mislead a consumer acting reasonably under the circumstances, and when the representation, omission, or practice is material to the consumer’s decision or conduct.² The test does not ask whether astronomers are misled. It asks whether the reasonable consumer is misled. The reasonable consumer is not an astronomer.

II. The Name

The product under review is called the equinox. The word is formed from the Latin aequus, meaning equal, and nox, meaning night. It entered English in the fourteenth century carrying this meaning on its face, and it has carried it ever since.³

Standard dictionaries define the equinox as either of the two times each year when the sun crosses the plane of the Earth’s equator and day and night are of approximately equal length everywhere on Earth. The name is not decoration. It is the product’s central claim, printed in the title of every calendar entry, every almanac table, and every dictionary definition, and repeated each September and March by every television weatherman in America. As one astronomy writer observed, television weathermen are sure to say “days and nights are equal today,” even though it is never true.⁴

The claim is material. People plan around it. Schools teach it. The first day of fall is announced on its authority. A consumer purchasing a calendar, consulting an almanac, or watching the weather is entitled to receive the equal night the name advertises.

III. The Event

The September equinox of 2026 occurs at a single instant: 00:05 Coordinated Universal Time on September 23, 2026. In the United States that instant falls on Tuesday, September 22: 8:05 PM Eastern, 7:05 PM Central, 6:05 PM Mountain, and 5:05 PM Pacific Daylight Time.⁵ At that moment the sun crosses the celestial equator heading south, and the Northern Hemisphere passes from longer days to longer nights.

This is the geometry the dictionaries describe. It is the instant the calendars mark. It is, by every commercial account, the date of equal day and equal night.

IV. The Shortfall

On that date, day and night are not equal anywhere on Earth.

At the equator, the day exceeds the night by approximately fourteen minutes. At mid-temperate latitudes the excess is approximately eight minutes. The equinox carries between four and fifteen minutes more day than night, depending on latitude, with the excess growing toward the poles. At the South Pole, the researchers stationed there experience twenty-four hours of daylight on the equinox. No trace of night. No sign of equality. Just the sun, fully up, rolling along the horizon.⁶

The word equinox comes from the Latin for equal night, as the weather services themselves acknowledge, but as one major weather publisher put it, “that’s not quite what happens on that day.”⁷ The discrepancy is not a rounding error. It is the entire product claim, and it is false in every market in which the product is sold, including the market at the equator, where the claim of equal day and night is most explicit and the shortfall is fourteen minutes.

V. The Two Adjustments

The shortfall has two causes, and both are known to the sellers.

First, the sun is a disk, not a point. Sunrise and sunset are defined as the moments when the upper limb of the sun, its leading edge, first appears above or finally disappears below the horizon, even though the center of the disk is still below the horizon at both instants. The sun’s apparent radius, its semidiameter, is approximately sixteen arcminutes. Counting from the upper limb rather than the center adds a few minutes of daylight at each end of the day.⁸

Second, the Earth’s atmosphere refracts sunlight. Near the horizon the atmosphere lifts the sun’s apparent position by approximately thirty-four arcminutes, nearly the sun’s own angular diameter. An observer sees the sun before it has geometrically risen and after it has geometrically set. In the standard sunrise and sunset tables, the assumed refraction is thirty-four arcminutes and the assumed solar semidiameter is sixteen arcminutes, and their combination means that when the upper limb of the sun is on the visible horizon, its center is fifty arcminutes below the geometric horizon.⁹

These are not obscure findings. The thirty-four arcminutes and the sixteen arcminutes are the working assumptions of every published sunrise and sunset table, including the tables printed in the very almanacs that advertise the equal night. The sellers publish the correction and the claim in the same book. The correction is in the tables. The claim is in the title. The reasonable consumer reads the title.

VI. The Actual Product

The product as advertised does exist. It is called the equilux, and it is sold on a different date, under a different name, to almost no one.

The equilux is the day on which day and night are actually equal. Unlike the equinox, which is a whole-Earth event occurring at a single instant worldwide, the equilux is latitude-dependent. At mid-northern latitudes it falls a few days after the autumnal equinox, toward the winter side. A classroom that followed its sunrise and sunset times found the twelve-hour day arriving three days after the reported first day of autumn.¹⁰

Within two degrees of the equator, there is no equilux at all. At those latitudes the changes in day length through the year are smaller than the refractive excess, and the day is longer than the night on every day of the year. For the roughly one in twelve human beings who live within two degrees of the equator, the product advertised as equal night is never available, on any date, at any price.¹¹

The existence of the equilux is the sellers’ worst fact. It proves they know what equal day and night looks like, they know when it occurs, they have a name for it, and they have chosen to sell the public a different date under the equal-night name anyway.

VII. The Sellers

The representation is made in commerce. Almanac publishers sell the date. Calendar publishers sell the date. Dictionary publishers sell the definition. Broadcasters sell the advertising inventory around the weather segment in which the claim is repeated. The statute reaches acts or practices “in or affecting commerce,” and the sale of calendars is commerce.

The sellers cannot plead ignorance. The almanac that prints “equal day and night” computes its sunrise tables with the thirty-four arcminutes of refraction that make the equality impossible. The weather publisher that writes “that’s not quite what happens on that day” prints the equinox date in the same article. The weatherman who says “days and nights are equal today” is contradicted, in print, by the astronomers his own station consults.¹²

Knowledge plus continued representation is the textbook pattern the deception framework was written to address. The representation is the product’s name. The omission is the refractive excess. The consumer acting reasonably under the circumstances believes the Latin.

VIII. The Defense

The objections are obvious and must be stated plainly, because the genre of honest inquiry requires that the defense be heard before it is overruled.

First, the astronomers’ definition is geometric, not photometric. The equinox marks the instant the sun’s center crosses the celestial equator. It was never, the defense says, a promise about the observed length of daylight. The name describes the geometry, and the geometry is exactly as advertised.

Second, no consumer was harmed. Nobody lost money because September 22 had eight extra minutes of daylight. The deception framework requires materiality, and eight minutes of unexpected sunshine is not material to any decision any consumer has ever made.

Third, the name is seven hundred years old. The Latin predates the Commission by six centuries. One cannot retroactively prosecute a word, and the statute was not written to adjudicate etymology.

Fourth, refraction is physics, not fraud. The atmosphere bends light without anyone’s permission and without commercial motive. The sellers did not create the refractive excess, and they cannot be liable for the optics of the planet.

Fifth, the meteorologists have their own calendar. Meteorological fall began on September 1, three weeks before the equinox. The seasons were already underway. The equinox date governs nothing, so misdescribing it deceives no one.

The defense is eloquent, and it fails on the text. The statute asks about the reasonable consumer, not the astronomer. The reasonable consumer does not know the sun’s center from its upper limb. The statute asks whether the representation is likely to mislead, not whether the misleading was profitable. Materiality is measured against the consumer’s understanding of the product, and the product’s name is its entire description. The dictionaries, the final authority on what words mean to reasonable consumers, still define the equinox as the time of approximately equal day and night, and “approximately” is doing fourteen minutes of work at the equator and twenty-four hours of work at the South Pole.

As for the age of the word: the statute contains no grandfather clause for Latin. A representation that was deceptive in the fourteenth century does not become truthful through repetition. It becomes a continuing violation.

IX. The Remedy

The remedy follows the violation. The equinox must be relabeled. Every calendar entry, almanac table, dictionary definition, and weather-segment script that represents the equinox as the date of equal day and night must carry a correction: the day exceeds the night by four to fifteen minutes depending on latitude, by fourteen minutes at the equator, and by the entirety of the night at the South Pole.

The equilux dates, the actual dates of equal day and night, should be printed where the equinox dates are now printed. In the equatorial band, where no equilux exists, the entry should read as the tables require: no equal night available.

Section 45(m) provides civil penalties for knowing violations of the Act following a Commission determination. The sellers have published the refractive data alongside the false name for as long as both have existed, which is the entire history of the modern almanac. Knowledge is not the issue. The correction notice is.

The Commission has ordered corrective advertising for less than a mislabeled season. It should order it here. The sun will still cross the celestial equator at 00:05 UTC on September 23. It will simply have to do so under its true description, which is: mostly day, everywhere, with the night arriving several days late.

Ergo.