Rahu Kaal (राहु काल) is a period of about 90 minutes that comes once every day and is considered inauspicious for starting important work. You find it by dividing the time from sunrise to sunset into eight equal parts. One of those parts, fixed by the weekday, is Rahu Kaal. Because sunrise and sunset change every day, the clock time of Rahu Kaal changes too.
In Nepali and Hindu households it is one of the most common timing rules. People move a shop opening, a wedding errand, a deal signing or the start of a long trip by an hour or two so that it does not begin inside Rahu Kaal.
This guide covers what Rahu Kaal means, how to calculate it step by step, which slot each weekday uses, and why the exact time depends on your location and the season.
What does Rahu Kaal mean?
Rahu Kaal is the part of the daytime ruled by Rahu, the shadow planet (a lunar node) in Vedic astrology. It lasts one-eighth of the daylight, which is about 90 minutes when day and night are nearly equal. By tradition it is a bad time to begin auspicious or important tasks.
Rahu is not a physical planet. In classical Hindu astronomy it is the north lunar node: the point where the Moon's path crosses the ecliptic, the Sun's path in the sky. Rahu is linked with sudden disruption, confusion and obstacles, so the slot it rules is treated as a poor time to begin anything you want to go smoothly.
Rahu Kaal applies mainly to the start of an activity. Work that is already in progress can continue. If you started a task before Rahu Kaal, you do not need to stop it when Rahu Kaal begins.
How is Rahu Kaal calculated from sunrise to sunset?
Take the full daylight length, from sunrise to sunset, and divide it into eight equal parts. Each part is one slot. Rahu Kaal is exactly one of the eight slots, and the weekday decides which one.
Step by step:
- Find the local sunrise and sunset times for your place and date.
- Subtract the sunrise time from the sunset time to get the length of daylight.
- Divide that length by eight. The result is the length of one slot.
- Count forward from sunrise to the slot for today's weekday (see the table below). That slot is Rahu Kaal.
Example: the Sun rises at 6:00 AM and sets at 6:00 PM. That is 12 hours of daylight. Divided by eight, each slot is 90 minutes. Slot 1 is 6:00 to 7:30, slot 2 is 7:30 to 9:00, slot 3 is 9:00 to 10:30, and so on. Slot 1 is never Rahu Kaal. On a Monday (slot 2), Rahu Kaal on this day would be 7:30 to 9:00 AM.
The same divide-by-eight method is used for several other daily timings listed in a daily Panchang reading.
Why the duration is rarely exactly 90 minutes
Rahu Kaal is exactly 90 minutes only when daylight is exactly 12 hours, which happens near the equinoxes in March and September. In summer the days are longer, so every slot, including Rahu Kaal, is longer than 90 minutes. In winter the days are shorter, so every slot is shorter. The slot is always one-eighth of that day's daylight, never a fixed block of clock time.
For example, if a winter day has sunrise at 7:00 AM and sunset at 5:24 PM, daylight is 10 hours 24 minutes (624 minutes). One slot is 624 ÷ 8 = 78 minutes. On a Wednesday (slot 5), Rahu Kaal starts 4 × 78 = 312 minutes after sunrise, so it runs from 12:12 PM to 1:30 PM.
What is the weekday order of Rahu Kaal slots?
Each weekday has a fixed Rahu Kaal slot, and it is never the first slot of the day. Sunday uses the 8th slot and Monday the 2nd. The table gives the slot number and the approximate time for a 6:00 AM to 6:00 PM day.
| Weekday | Slot number (of 8) | Approx. time (6 AM-6 PM day) |
|---|---|---|
| Sunday | 8th | 4:30 PM - 6:00 PM |
| Monday | 2nd | 7:30 AM - 9:00 AM |
| Tuesday | 7th | 3:00 PM - 4:30 PM |
| Wednesday | 5th | 12:00 PM - 1:30 PM |
| Thursday | 6th | 1:30 PM - 3:00 PM |
| Friday | 4th | 10:30 AM - 12:00 PM |
| Saturday | 3rd | 9:00 AM - 10:30 AM |
A common memory aid is "Mother Saw Father Wearing The Turban Suit". The first letters stand for Monday, Saturday, Friday, Wednesday, Thursday, Tuesday and Sunday, in order from slot 2 to slot 8. You do not have to memorise it if you use a panchang. The times in the table are only approximate and shift with the real sunrise and sunset.
Why do exact Rahu Kaal times vary by location and season?
Sunrise and sunset depend on latitude, longitude and the time of year, so Rahu Kaal does too. Kathmandu, Pokhara, Biratnagar and Sydney all have different sunrise times, so each place gets a different Rahu Kaal window on the same weekday.
Two things cause the difference:
- Location: places further east have an earlier sunrise, and latitude changes how long the day is. Both move the eight slots.
- Season: daylight is longest near the summer solstice (around 21 June) and shortest near the winter solstice (around 21 December), so the slot length grows and shrinks through the year.
For this reason a single printed table for the whole year can be wrong by a good margin. Use a tool that works out sunrise and sunset for your place and date, then takes the slot from that. The Nepali Calendar app does this for Nepal: it calculates each day's Rahu Kaal from that day's actual sunrise and sunset in Kathmandu. If you live far from Kathmandu, and especially if you live abroad, repeat the division with your own local sunrise and sunset.
The same sunrise-based method is used when picking an auspicious wedding date and Saait.
Rahu Kaal and the rest of the Panchang
Rahu Kaal is one of several daily timing markers. The others include Gulika Kaal and Yamaganda. The panchang also lists five main elements for each day: tithi, vara (weekday), nakshatra, yoga and karana. See the five elements of the Panchang for how they fit together, and the 27 nakshatras and their meanings for the Moon's daily star.
More tools on Katigate
Frequently Asked Questions
Can I do important work during Rahu Kaal?
Rahu Kaal mainly rules out starting an important new task, such as signing a deal, setting out on a trip or opening a business. Work already under way can continue. Many people also treat daily routine tasks and the worship of certain deities as unaffected by Rahu Kaal.
Is there a Rahu Kaal at night?
The standard Rahu Kaal is a daytime period only, found by dividing sunrise-to-sunset daylight into eight parts. Some traditions also calculate a night version by dividing the time from sunset to the next sunrise into eight slots. Most Nepali calendars and panchang listings show only the daytime Rahu Kaal.
Why is Rahu Kaal never in the first slot of the day?
The first daylight segment is never assigned to Rahu in this method. The remaining segment depends on the weekday. Do not assume a fixed three-hour clear period: each segment is one eighth of that location’s daylight duration, so its length changes with the season.
How accurate are printed Rahu Kaal tables?
A printed table based on a fixed 6 AM to 6 PM day is only a rough guide. Real sunrise and sunset differ by city and season, sometimes by 30 minutes or more, and that moves every slot. For the correct window, use a panchang that calculates the actual daylight for your date and place.