Rahu Kaal Today

Rahu Kaal is one eighth of the daylight, marked as inauspicious, and which eighth it is depends only on the day of the week. The tool above computes today's window for your city from your local sunrise and sunset.

It also shows the working, because the working is short and it settles most of the questions people arrive with.

The construction, in full

Take the interval from sunrise to sunset and divide it into eight equal parts. Number them one to eight. Each weekday is assigned one of those numbered parts, and that part is Rahu Kaal.

The assignments are:

That is the whole calculation. Nothing else enters it.

Two things follow immediately, and both are checkable against the table above. The first eighth of the day is never Rahu Kaal, on any weekday. The assignments run from two to eight, and one is simply not used. And the assignment is irregular: there is no arithmetic step that takes you from Sunday's eighth to Monday's to Tuesday's. It goes 8, 2, 7, 5, 6, 4, 3, which is a list to be memorised rather than a rule to be derived.

Why the name is misleading

This is the single most common misunderstanding, and it is worth stating plainly because it is easy to verify.

Rahu Kaal is named for Rahu, the ascending lunar node. But the calculation never looks up Rahu's position. It never looks up any planet's position. It needs your sunrise, your sunset, and today's weekday, and nothing else.

You can test this on the page itself. Change the ayanamsa selector. Every planetary longitude on the site moves by more than a degree, Rahu's included. The Rahu Kaal timing does not change by a single second, because there is no planetary position in the formula for it to depend on.

Rahu Kaal is an ordinal into the eight parts of daylight, assigned by weekday. It is a calendar convention, not an astronomical measurement. The only astronomy in it is the sunrise and sunset that set the window's boundaries.

That is not an argument against observing it. Plenty of practices are conventions and are observed anyway. But it does mean that anyone offering to compute a more astronomically accurate Rahu Kaal for you is offering something that does not exist.

Why the window is a different length every day

Because it is a fraction of daylight, not a fixed number of minutes, and daylight changes with the season.

At Delhi's latitude, one eighth of the daylight runs from about 77 minutes at the December solstice to about 105 minutes at the June solstice. That is a swing of nearly half an hour between the shortest and longest Rahu Kaal of the year.

The swing depends on how far you are from the equator, and the pattern is worth seeing:

Chennai sits nearer the equator, so its days vary less and its Rahu Kaal is more nearly constant. London's varies by more than an hour across the year, which is why a Rahu Kaal table printed for India is close to meaningless if you are in Britain.

There is one date where all of this collapses into a single number. At the equinoxes, day and night are close to equal everywhere on Earth, so one eighth of the daylight is close to 91 minutes in every city. Delhi and Chennai both come out at 90.8 minutes on 20 March 2026, matching to a tenth of a minute despite being nineteen degrees of latitude apart.

Yamaganda and Gulika, and what their tables give away

Yamaganda and Gulika Kalam are built exactly the same way: one eighth of the daylight, selected by weekday. Only the assignment table differs.

Reading down the Gulika column shows something the Rahu column does not have. It descends by exactly one each weekday: 7, 6, 5, 4, 3, 2, 1. Yamaganda does the same thing with a wrap, running 5, 4, 3, 2, 1 and then round to 7, 6. Both of those are rules. Rahu Kaal's column is the only one of the three that is not.

And where Rahu Kaal never occupies the first eighth, Gulika and Yamaganda never occupy the eighth one. Between the three of them, the first and last eighths of any day carry exactly one marked window rather than two.

None of that tells you anything about whether the windows mean anything. It does tell you that they were constructed, deliberately, by somebody arranging ordinals, which is a different kind of object from a planetary position.

Why another site gives you a different time

Four reasons, and none of them is that one site has better astronomy than the other.

A different sunrise definition. This is the big one, and it behaves in a way nobody expects.

The common civil definition puts sunrise when the upper limb of the Sun crosses the horizon corrected for atmospheric refraction, which works out to the centre of the disc sitting about 50 arcminutes below the true horizon. Some traditional panchangs instead use the geometric centre of the disc with no refraction at all. At Indian latitudes the two differ by three to five minutes. In Delhi on 11 August 2026 the refracted convention gives sunrise at 05:48 and the geometric one gives 05:52, a gap of 3.9 minutes.

Now here is the part that is not obvious. A later sunrise also means an earlier sunset by the same amount, so the daylight interval shrinks at both ends and each eighth gets shorter. Those two effects fight each other. The start of the Nth eighth sits at sunrise plus N minus one eighths, so if sunrise moves later by some amount, that eighth's start moves later by that amount but earlier by N minus one quarters of it. Written out, the shift is the sunrise shift multiplied by one minus a quarter of N minus one.

Set that to zero and you get N equal to five. The boundary between the fourth and fifth eighths does not move at all, because it is the midpoint of daylight, which is local apparent noon, and noon does not care which sunrise definition you picked. Windows near noon barely shift. Windows near the ends shift most. And windows on opposite sides of noon shift in opposite directions.

The Delhi figures bear this out exactly. On that Tuesday, Gulika is the fifth eighth and its start time is identical under both conventions. Yamaganda is the third eighth and starts two minutes later under the geometric convention. Rahu Kaal is the seventh and starts two minutes earlier. Two of the three moved, in opposite directions, from a single four-minute change at sunrise.

Different coordinates for the same city. Cities are large. A site holding the coordinates of one suburb and a site holding another will get sunrise times a minute or two apart, and the window moves with them.

A different city entirely. Sunrise in Kolkata is roughly forty minutes earlier than in Mumbai. A single Rahu Kaal quoted "for India" is quoted for whichever city the publisher chose, and it is wrong everywhere else by a comparable amount.

Which is being reported. Rahu Kaal, Yamaganda and Gulika all look alike, being an eighth of the day with a start time and an end time, and they are easy to confuse in a table that does not label them clearly.

This page states which sunrise convention it used and shows the resolved sunrise, so a disagreement can be traced rather than argued about.

What this page will not tell you

It will not tell you that something bad will happen to you between 15:45 and 17:24.

The tool computes a window. Whether that window carries any consequence is not a question arithmetic can answer, and this page makes no claim either way. What it will not do is dress the convention up as astronomy in order to make it sound more authoritative than it is.

Worth knowing if you are deciding how much weight to give it: Rahu Kaal is a muhurta convention, not an astronomical one, and it belongs to the later practical almanac tradition rather than to the earliest astronomical literature. It is observed far more consistently in South India than in the north, and there are practising traditions that pay it little attention at all. A convention with that much regional variation in whether it is observed is not a good candidate for a universal law.

How it is used, practically

The usual practice is to avoid beginning something new during the window rather than to avoid the window entirely. Signing an agreement, setting out on a journey, opening a business, making a significant purchase: these are the sorts of things people postpone by ninety minutes. Ongoing work is generally not interrupted, and the window is not treated as dangerous in itself.

A few practical notes that follow directly from the construction:

Because Rahu Kaal is never the first eighth, the period immediately after sunrise is always clear of it. On most days that is a usefully long stretch.

Because the window is a fraction of daylight, it moves with the season and cannot be memorised as a clock time. "Rahu Kaal is 4:30 to 6:00 on Tuesdays" is true for a few weeks a year and wrong for the rest.

And because it is computed from local sunrise, it must be computed for where you actually are. If you have travelled, the table you are used to no longer applies.

A worked example, start to finish

Delhi, Tuesday 11 August 2026, using the refracted convention.

Sunrise is 05:48 and sunset is 19:04, so the daylight interval is 13 hours and 16 minutes. Divide that by eight and each part is 99.5 minutes, a little under an hour and forty.

Tuesday takes the seventh eighth for Rahu Kaal. Six parts have to elapse first, so that is six times 99.5, or 597 minutes, which is 9 hours and 57 minutes after sunrise. Add that to 05:48 and Rahu Kaal begins at 15:45 and runs to 17:24.

The same arithmetic gives the other two. Tuesday's Yamaganda is the third eighth, so two parts elapse first and it runs 09:07 to 10:46. Tuesday's Gulika is the fifth, so four parts elapse and it runs 12:26 to 14:05, straddling local noon as the fifth eighth always does.

Notice how much of the working there is: four numbers and two multiplications. Anyone quoting you a Rahu Kaal can be checked in under a minute, provided they tell you the sunrise they used. That is the reason this page shows it.

Where the sunrise itself comes from

Everything above rests on two instants, sunrise and sunset, so it is worth saying where those come from and what could go wrong in them.

The weekday is determined by the Hindu convention, in which a day runs sunrise to sunrise rather than midnight to midnight. That matters more than it sounds: a moment after midnight but before sunrise still belongs to the previous weekday, and so takes the previous weekday's Rahu Kaal assignment. This is a real source of off-by-one errors, and it is the kind that produces a plausible-looking wrong answer rather than an obvious one.

Sunrise and sunset come from astronomy-engine, with the topocentric correction applied. Rise and set times are the one place on this site where an observer's position on the Earth's surface genuinely matters, as opposed to planetary longitudes, which are computed geocentrically. The time-zone offset is resolved for the date you asked about rather than assumed, which matters for historical dates in India, where Bombay kept UTC+04:51 until 1955 and Calcutta kept UTC+05:53:20 until 1948.