Today's Planetary Hora — All 24, Derived

Rank the seven classical graha by how slowly they appear to move against the stars and you get the Chaldean order: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon. Saturn’s circuit is 29.46 years, Moon’s is 27.32 days, and the other five fall in between. Every hora system in the ancient world walks this list.

Except that the ranking does not quite settle it, and this site’s own numbers are where that shows. Rank the seven by the circuit lengths stored in this repo and you fix 4 of the seven places; the remaining 3 are a tie. Sun, Venus and Mercury all read 365.26 days, because Venus and Mercury never leave the Sun’s neighbourhood and their geocentric period simply is the Sun’s. Which is the ambiguity the ancient sources actually differ on — Venus before Mercury, or the reverse — and it is not a small one. Break the tie the other way, step by three again, and two weekdays change hands: Wednesday and Friday. The week we have is the week one of those two readings produces, and the periods on their own cannot tell you which. That is computed here rather than asserted; if the stored periods ever stopped tying in exactly one place, or the swap ever moved a different number of days, the build would stop.

A hora is one twelfth of the daylight, or one twelfth of the night. Twenty-four of them cover a sunrise-to-sunrise day, and each takes the next graha in the cycle. Start the list at the Sun — Sun, Venus, Mercury, Moon, Saturn, Jupiter, Mars — and count off twenty-four. Twenty-four is three full turns of a seven-name cycle plus three, so you land three places along from where you began. Sunday’s first hora belongs to the Sun; twenty-four horas later the next day opens on the Moon, three places on. Which is Monday. Run it again and you get Mars, then Mercury, Jupiter, Venus, Saturn — the seven weekdays, in the order they are still named in, in Hindi and in English alike.

That is worth pausing on, because it inverts the way the hora table is usually taught. The sequence is not derived from the weekday. The weekday is derived from the sequence. A week of seven days in this specific order is a fossil of a twenty-four-hour day laid over a seven-name cycle, and the hora chart above is that fossil still running. In this site’s code the relationship is asserted rather than assumed: stepping the Chaldean order by three has to reproduce the weekday lords, or the build stops.

The last column is the other consequence of that remainder. Twenty-four horas shared among seven graha is three each with three left over, so on every weekday exactly three graha hold four horas and the other four hold three — and the three that get the extra one are always the weekday’s own lord and the next two along the cycle, because the remainder is taken off the front of the sequence. The distribution is different on all seven days, and it is why a graha’s share of a day is a property of the weekday rather than a constant.

The fourth column is the same system seen from the choghadiya side. Choghadiya cuts the same two spans into eight instead of twelve and walks the same cycle, so the two charts are one machine at two gear ratios. Twelve horas carry you five places along a seven-name cycle, and five forward is two back — which is exactly where the night choghadiya opens. So the thirteenth hora and the first slot of the night share a graha on all seven weekdays, and the first hora and the first slot of the day do too. Neither page had ever said so.

Twelve pieces of daylight only make sixty-minute hours on the day daylight lasts twelve hours. Every other day of the year a day hora and a night hora differ, and near a solstice they differ a lot. Across the 729 sunrise-to-sunrise spans this site’s ephemeris table brackets for New Delhi — 1 January 2026 to 30 December 2027 — the range is:

Those figures are exact, not rounded, and the reason is a small piece of luck. Sunrise and sunset are tabulated to the whole minute, so a daylight span is a whole number of minutes — and a twelfth of M minutes is exactly five M seconds, always a whole number. A hora therefore always lands on a whole second. It is never necessary to say “about seventy minutes”, which is what this page used to say.

A day hora is longer than a night hora on 391 of the 729 days, and the lead changes hands 4 times inside the table — 16 March 2026 to the day half, 28 September 2026 to the night half, 17 March 2027 to the day half, 28 September 2027 to the night half. Those dates sit a few days off the equinoxes because sunrise and sunset are defined at a solar zenith of 90.833 degrees rather than 90, the standard allowance for refraction and the Sun’s own width: visible daylight passes twelve hours before the March equinox and stays above it for some days after the September one.

One boundary needs no ephemeris at all. Six twelfths is half the daylight, so hora 7 begins at local apparent noon — the midpoint of sunrise and sunset, which is not 12:00 on the clock — on every day of the year, at every latitude. That is checked against all 729 spans in the table rather than asserted, and it is the same instant the 4th and 5th choghadiya meet at. Abhijit, the eighth of fifteen parts of daylight, straddles it and is 12/15 of a hora exactly — 80% of one — on any day, anywhere.

Charts circulate that add a Rahu hora or a Ketu hora, sometimes as a ninth and tenth name, sometimes replacing one of the seven. The Chaldean order cannot accommodate them. It is a ranking by apparent speed against the fixed stars, and the nodes are not bodies — they are the two points where the Moon’s orbital plane cuts the ecliptic. They have no disc, no light of their own and no independent motion to rank. Seven graha, seven names, twenty-four horas: the arithmetic has no room for a ninth term and the tradition never asked it to hold one.

This site does record a weekday for both nodes — Saturday for Rahu, Tuesday for Ketu — and that is a different claim: it is the day on which their remedies are traditionally done, borrowed from the graha each node is said to behave like. It is not a rulership, so it generates no hora. The code enforces the distinction: the hora sequence throws if a node ever resolves into it.

Two more things this page will not do. It will not tell you what to do in a hora. The subjects in the tables above are what each graha is given charge of in this site’s planet pages, and the leap from a subject to an instruction is exactly the leap this page used to make when it called one hora the most auspicious for weddings and another unfavourable for new beginnings. And it will not compute a minute of its own: sunrise and sunset come from a generated table built on the JPL DE421 ephemeris, and every boundary is arithmetic on those two numbers.

The clock times are New Delhi’s. Longitude moves every boundary — sunrise in Kolkata is nearly an hour earlier than in Ahmedabad — so the sequence above is yours and the minutes are Delhi’s. The panchang pages carry sunrise, sunset and the three set-aside windows for 38 cities.