Choghadiya vs Rahu Kalam: Two Muhurta Windows to Track
Choghadiya divides your day into eight windows; Rahu Kalam is one specific inauspicious slot, calculated separately. Here's how each works and which to check.
Choghadiya and Rahu Kalam are both muhurtas, time windows the tradition uses to plan a day, defined by the same basic math: that day’s sunrise to sunset, divided into eight parts. Choghadiya names all eight of those windows, four favorable and three unfavorable, so you can pick a good one to start something. Rahu Kalam is a single window, always unfavorable, calculated by weekday, and the tradition treats it as worth avoiding no matter what else is going on that day. Check Choghadiya when you’re choosing a good time. Check Rahu Kalam when you’re ruling one out.
What Choghadiya actually divides
Choghadiya (also seen as Chaughadia) splits daylight hours into eight equal windows, and does the same again for the night (sunset to the next sunrise), sixteen windows in a full day-night cycle. Each window carries one of seven traditional labels: Udveg, Chal, Labh, Amrit, Kaal, Shubh, and Rog. Amrit, Shubh, and Labh are the most favorable for starting something important. Chal is moderately favorable, useful for travel. Udveg, Kaal, and Rog are inauspicious.
With seven labels and eight windows, one label has to repeat each day. The weekday fixes which label opens the sequence, which in turn fixes the order of all eight. Wednesday’s daytime sequence, for instance, runs Labh, Amrit, Kaal, Shubh, Rog, Labh, Udveg, Chal, in that order from sunrise. A different weekday starts somewhere else in the cycle entirely. Because the whole system is built from sunrise, the actual clock time of each window is unique to wherever you are, not just which day it is.
What Rahu Kalam actually is
Rahu Kalam doesn’t come from the seven-label Choghadiya cycle at all. Instead, you still divide daylight into eight parts, and a fixed weekday table marks just one of those eight slots as Rahu Kalam. Monday, it’s the second slot. Wednesday, the fifth. The weekday assignment is fixed; only the clock time moves, shifting with your local sunrise and sunset. Standard panchang references, including DrikPanchang, compute Rahu Kalam the same way: local daylight divided into eight equal parts, with a fixed weekday table marking the inauspicious slot.
The tradition holds that new beginnings — signing a contract, starting a trip, opening a business for the first time — are best delayed until Rahu Kalam passes. It’s usually between about 75 minutes and two hours long, depending on the season and your latitude, since it’s always exactly one-eighth of that day’s daylight.
Choghadiya vs Rahu Kalam, side by side
| Choghadiya | Rahu Kalam | |
|---|---|---|
| What it measures | All eight day windows (and eight more at night), each labeled | One specific window per day |
| How it’s calculated | Sunrise-to-sunset split into eight, cycling through seven labels in a weekday-set order | Sunrise-to-sunset split into eight, weekday fixes which single slot it is |
| Typical use | Choosing a favorable window to start something | Knowing which window to avoid |
| Length | About 75 minutes to 2+ hours per window, depending on season and latitude | Same, since it’s one Choghadiya-length window |
A worked example: London, Wednesday, 15 July 2026
On this date, London’s sun rises at about 5:01 am and sets around 9:13 pm, about 16 hours and 11 minutes of daylight. Divided into eight equal parts, each Choghadiya window runs a bit over two hours.
Wednesday’s daytime sequence starts with Labh at sunrise. Following it through: Labh (5:01–7:02 am), Amrit (7:02–9:04 am), Kaal (9:04–11:05 am), Shubh (11:05 am–1:06 pm), Rog (1:06–3:08 pm), Labh again (3:08–5:09 pm), Udveg (5:09–7:11 pm), and Chal (7:11–9:13 pm).
Wednesday’s Rahu Kalam falls in the fifth window of the day, which lands at 1:06–3:08 pm. On this particular Wednesday, that also happens to be the Rog window, already unfavorable on its own, so the two systems agree here.
None of this comes from a table printed for Delhi or Chennai — London’s own sunrise and sunset set both the Choghadiya windows and the Rahu Kalam slot, and they don’t match India’s.
Using both together
Amrit, Shubh, and Labh windows are the ones the tradition points to for starting something important. Rahu Kalam is the one exception that overrides all of them: even if a favorable Choghadiya window happens to overlap with that day’s Rahu Kalam, tradition treats Rahu Kalam as the deciding factor and waits for it to pass. Favorable label or not, that overlap is skipped.
A common mix-up
Rahu Kalam isn’t just “the bad Choghadiya slot.” It’s a separate calculation that happens to land inside one of the eight Choghadiya windows, which is exactly why the two get confused. Rahu Kalam is fixed by weekday. Choghadiya’s inauspicious windows (Udveg, Kaal, Rog), however, shift position depending on the day.
Another common mistake, especially outside India, is using a Choghadiya or Rahu Kalam table computed for an Indian city and assuming those clock times apply where you live. They don’t. Muhurtha computes both on-device from your exact coordinates, not a fixed reference city, so the windows update automatically as your local sunrise and sunset shift through the year.
If you want Choghadiya and Rahu Kalam computed automatically for wherever you actually live, Join the Beta Founders Circle to try Muhurtha before public launch.
FAQ
Is Rahu Kalam part of Choghadiya?
Not exactly. Both are calculated by dividing daylight hours into eight equal windows, but Choghadiya assigns a rotating label to all eight, while Rahu Kalam is a separate weekday-based rule that marks just one of those eight as inauspicious. They use the same underlying math, applied differently.
How long does Rahu Kalam last?
About 75 minutes to two hours, depending on the season and your latitude. It’s always exactly one-eighth of that day’s daylight hours, so it’s longer in summer and shorter in winter.
Can Rahu Kalam fall during an auspicious Choghadiya window?
Yes. Depending on the weekday, Rahu Kalam can land inside a Choghadiya window that’s otherwise labeled favorable. When that happens, tradition treats Rahu Kalam as the override — the favorable label doesn’t count for that window.
Do Choghadiya and Rahu Kalam change with the seasons?
The clock times do, because both are calculated from sunrise and sunset, which shift through the year. The weekday sequence and the Rahu Kalam rule itself stay fixed; only the actual times they land on move.
Which one should I check before starting something important?
Check Choghadiya to find a favorable window, and check Rahu Kalam to make sure that window doesn’t overlap with it.