The hour of the Rat

Most people know their year animal and stop there. The same twelve animals also run through the day: each one takes up two of the twenty-four hours. The Rat has ended up with the strangest shift of all – the one around midnight, where the date turns over.

Twelve animals, one day

Before mechanical clocks reached East Asia, the day was divided not into twenty-four hours but into twelve stretches. Each carried the name of an earthly branch, that is, of one of the twelve animals, and lasted twice as long as the modern hour. This was no scholarly quirk but ordinary life: arrangements were made for the hour of the Rabbit, not for six o’clock.

It can still be heard in the language today. The Chinese word for the modern hour means literally “small hour” – small because it is only half as long as the stretch it replaced. The Western clock has won out; the name recalls the division that came before.

Why the Rat gets midnight

The hour of the Rat runs from 11 p.m. to 1 a.m. It is the first of the twelve, and the only one that crosses the boundary of the day: its first half still belongs to the evening, its second already to the next morning. The count therefore starts neither at getting up nor at sunrise, but at the darkest place in the round. In the course of the year the Rat sits at the matching place: its month is the one the winter solstice falls in. Day and year are built to the same pattern, only on different scales.

The early and the late Rat hour

From this follows a peculiarity that trips up anyone who has a Chinese birth chart worked out twice. The tradition distinguishes an early and a late Rat hour, that is, the half before midnight and the half after it. What it does not agree on is whether the early half already counts towards the coming day or still towards the one running out. Anyone born at 11:20 p.m. therefore ends up with two different day signs, depending on the method of reckoning.

This concerns one hour out of twenty-four, and the most sensitive piece of information of all hangs on it: in Chinese interpretation, the day sign is where the person themselves is read. Anyone born in that hour would do well to know both possibilities, rather than trusting the first table that comes to hand.

The watch on the wrist is not the clock in the sky

The second trap lies in the time itself. The double hours follow the position of the Sun; the clock follows an administrative decision. Since 1949 a single time zone has applied across China, from the far west to the coast; far in the west the Sun therefore stands highest only long after twelve. A time noted down there says little about where the Sun stood; some schools therefore convert it before making the assignment.

Closer to home is summer time. An hour’s shift sounds harmless, but here it is half a double hour, and so half the width of an animal’s stretch. A birth at 1:30 on a July morning already falls, by the clock, in the hour of the Ox; without summer time it would still be the hour of the Rat. Arithmetically, one birth time in two keeps the same hour animal in spite of the shift; the other does not.

What the hour adds

And what is all this effort for? The year of birth lumps a whole cohort together, the month and the day narrow it down, and the hour is the only detail that tells apart two people whose birthdays fall on the same date. Without it, what is left is a chart that fits everyone born on that date – a few hundred thousand of them worldwide.

If you know your birth time, the hour animal is settled in a few minutes. If it falls between 11 p.m. and 1 a.m., you were born in the one stretch that carries two dates at once – the only double hour, that is, where a decision has to be made before the interpretation. For how the twelve branches hang together, and what else besides the animal belongs in a Chinese birth chart, see Chinese astrology.