What is a hora? The planetary hours of the Vedic day

A hora is a planetary hour: one of the twenty-four divisions of a Vedic day, each ruled by one of the seven grahas, the moving bodies of traditional astronomy that give the weekdays their names. Twelve horas fill the daylight, from sunrise to sunset, and twelve more fill the night, from sunset to the next sunrise. Each is named for the graha that rules it, so a panchang, the traditional Hindu almanac, can say that this stretch of the morning belongs to Jupiter and the next to Mars.

Two things make the hora easy to misread. It is not the sixty-minute hour of the clock, and its order does not begin at midnight. This note covers the fixed order of the seven lords, how the weekday decides which lord opens the day, why twenty-four horas explain the order of the week itself, and how to work out the hora you are in from sunrise, sunset and a little arithmetic.

What a hora is

Tradition explains the word by taking ahoratra, the Sanskrit term for a full day and night, and dropping the syllable at each end, leaving hora.

The division is simple. Cut the daylight into twelve equal parts: each is one day hora. Cut the night into twelve: each is one night hora. Twelve and twelve make the twenty-four horas of one sunrise-to-sunrise cycle.

The hora is one of several ways the tradition divides the same day, each with its own count:

• Hora: twelve parts of the daylight and twelve of the night, one graha to each.
• Choghadiya: eight parts of each half, each carrying one of seven traditional names: Amrit (nectar), Shubh (good), Labh (gain) and Char (moving), which tradition favours, and Udveg (restlessness), Kaal (time) and Rog (illness), which it sets aside. What is choghadiya? sets out how those are read.
• Muhurta: one thirtieth of a whole day and night, about forty-eight minutes when day and night are equal.

All of them are counted from the local sunrise rather than from midnight, because the panchang day runs from one sunrise to the next. That single choice is what puts the small hours before dawn in the previous weekday, and there is more on it in why the Vedic day starts at sunrise.

The seven lords and the order they keep

The horas follow one fixed order, repeating without a break:

Sun, Venus, Mercury, Moon, Saturn, Jupiter, Mars, and then the Sun again.

That sequence looks arbitrary until you start it at Saturn. Read from there it runs Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon, which is how the tradition ranks the seven by their distance from the earth, from the farthest, Saturn, down to the nearest, the Moon. The hora order is that same ring, entered at a different point.

The weekday decides where you enter it. In a panchang the weekday is the vara, and each vara is named for a graha; the first hora after sunrise belongs to the lord of that vara. Thursday is Jupiter's day, so Thursday opens with a Jupiter hora. From there you simply walk the ring, one step per hora, straight through sunset and on to the next sunrise.

Because seven lords are shared out over twelve parts, the eighth hora of a half repeats the lord of the first. The table below walks one full Thursday, pairing each day hora with the night hora of the same number.

Any other weekday walks the same ring, entered at that day's own lord.

Why twenty-four horas set the order of the week

Follow that Thursday to its end and something tidy appears. The twenty-fourth hora of Thursday belongs to the Sun, so the next hora in the ring, the one that begins at Friday's sunrise, belongs to Venus. Venus is the lord of Friday.

The arithmetic behind it is small. Twenty-four horas divided among seven lords leaves a remainder of three, so each sunrise starts three places further along the ring than the last one did. Step through the order in threes from the Sun and you get the Sun, the Moon, Mars, Mercury, Jupiter, Venus, Saturn, which is the order of the days of the week.

This is the traditional explanation for why the week runs as it does, and it is the reason the sequence is never restarted at sunset. Run the twenty-four straight through and each new day arrives at its own lord.

How long a hora lasts, and how to find yours

A hora is an unequal hour. Its length is a fraction of real daylight or real darkness, so it stretches and shrinks as the seasons turn and it differs from one city to another. On a long summer day of fifteen hours, each day hora runs about seventy-five minutes while each night hora runs about forty-five. Only when both halves are twelve hours does a hora meet the clock's sixty minutes, and the farther a place sits from the equator, the wider that swing runs through the year. The note on the Vedic day works the figures for five cities on one date, from London to Sydney.

To find the hora you are in, four steps are enough:

1. Find your local sunrise and sunset for the day, and the next sunrise.
2. For a moment in daylight, divide the minutes from sunrise to sunset by twelve. For a moment at night, divide the minutes from sunset to the next sunrise by twelve.
3. Count how many whole parts have passed since that starting point. A moment in the nth part sits in hora n of that half.
4. Start at the lord of the weekday that began at the last sunrise, and step forward along the ring: n minus 1 steps for a day hora, and n plus 11 steps for a night hora, since the night continues the same count.

A worked example, with round illustrative figures: take a Thursday where sunrise is at 6:00am and sunset at 6:00pm. The daylight is 720 minutes, so each day hora runs 60 minutes. The fifth day hora therefore covers the stretch from 240 to 300 minutes after sunrise, and counting four steps on from Jupiter gives Mercury. A real day is rarely so tidy, and the arithmetic is the same either way.

How Sumuhurta reads the hora

Sumuhurta, the iPhone app this site is about, reads the hora as one input among several. It does not show a hora table, and it does not publish a ranking of the lords. What it looks at is how the lord of an hour sits for one particular chart: with an exact birth time it reads the lord against the lagna, the sign rising at birth, by the traditional reckoning of which houses that graha rules; without an exact birth time it falls back on whether the graha is one the tradition counts among the gentler ones. Alongside the hora it reads choghadiya, the abhijit muhurta around local noon and the Brahma muhurta before dawn, together with the chart itself.

What comes out is not a table but one to three personal windows in each sunrise-to-sunrise cycle, day or night, running from about twenty to a hundred and fifty minutes and never crossing sunrise or sunset. Each window carries a plain quality, Clear run, Sharp or Steady, and under it a quiet attribution naming the hora and the choghadiya at the middle of the window, in the form Mercury hora · Labh. Rahu Kaal, Yamaganda and Gulika, named in the rule below, are three classical daytime periods, each one of eight equal parts of the daylight and set by the weekday. The app's own rule for where a window may fall reads:

Every personal window Sumuhurta surfaces is calculated to avoid Rahu Kaal, Yamaganda, Gulika, and the Kaal, Rog and Udveg choghadiya periods.

That rule is deliberately narrow, and it is worth being plain about what sits outside it. The app does not perform a complete electional-muhurta assessment, the fuller traditional practice of choosing a moment for one particular occasion, which weighs many more factors. It does not replace a full panchang: there are no hora or choghadiya tables in it, no tables of the tithi (the lunar day) or the nakshatra (one of 27 star divisions along the Moon's path), and no times for the periods named in that rule. It does not predict outcomes, score a day or mark any part of it as a bad time. For a table of the horas in your city, or a reading for a particular occasion, a full panchang or a qualified practitioner is the right place. How it reads the day covers the rest of the calculation.

Common questions

Is a hora the same as an hour of the clock?

No. A clock hour is a fixed sixty minutes, while a hora is one twelfth of the daylight or of the night, so the two agree only when both halves are about twelve hours long, as happens near the equator or around the equinoxes.

Does the hora count restart at sunset?

No. The twelve night horas continue the same sequence of lords that began at sunrise, without a break. That unbroken run is what brings each new sunrise around to the next weekday's lord.

Which hora does tradition favour for beginning something?

In general the tradition looks to the horas of the gentler grahas, Jupiter, Venus, Mercury and the Moon, and treats the horas of Saturn, Mars and the Sun as better suited to other kinds of work. Practice varies by region and by family, and the hora is only one layer: a reading usually weighs the choghadiya and the daytime periods set out in the guide to Rahu Kaal, Yamaganda and Gulika alongside it.

How is a hora different from a choghadiya?

Both are counted from your own sunrise, but they cut the day differently. Choghadiya divides each half into eight named parts; the hora divides each half into twelve parts ruled by grahas. They drift in and out of step through the day, which is why a traditional reading often looks at both.

Can I see a hora table in Sumuhurta?

No. The app names the hora of each window in its attribution and shows nothing more of the sequence. A full panchang for your city lists all twenty-four.