Calculation of Rahu Kaal and its Importance in Muhurta

According to Vedic Astrology, a certain period of each day under the influence of Rahu is considered inauspicious.

Rahu is an inauspicious planet therefore the period of Rahu (Rahu Kaal or Rahu Kaal) is considered inauspicious and is avoided for any new venture.

According to Hindu mythology, Rahu is a snake that swallows the Sun causing eclipse.

The length of rahukaal is around 90 minutes (but keep varying depending upon the duration of the day at any specific place).

Doing Puja, Hawan or Yagya (यज्ञ) to propitiate auspicious planets during this time is interfered by Rahu due to its malefic nature. If one does Puja, Hawan or Yagya during Rahu Kaal then desired results are not achieved. Hence it is important to consider Rahu Kaal before starting any new work. By doing so, possibility of achieving desired results is increased. 

However any work related to Rahu gives good results during this period. Hawan, Yagya, etc. to propitiate Rahu can be done during this time. 

Auspicious activities like marriage rituals, engagement, Grih-Pravesh, any purchase of stocks, shares, gold, home, car and starting new business or trade are avoided during this time. Rahu Kaal is considered only for undertaking any new work and already started work can be continued during Rahu Kaal. 

Rahu Kaal is one of the eight segments of the day between sunrise and sunset. Eight segments of the day are calculated by taking the total time between sunrise and sunset at a given place and then dividing this time duration by eight. 

Total duration of the day (Dinman) is divided into eight equal portions.

First portion of the day is never a Rahu Kaal.

Second Part is Rahukaal on Monday,

Third part is rahukaal on Saturday

Fourth part is rahukaal on Friday

Fifth part is rahukaal on Wednesday

Sixth part is rahukaal on Thursday

Seventh part is rahukaal on Tuesday

Eight part is rahukaal on Sunday

On Wednesday and Friday Rahukaal coincide with Abhijit muhurta

The timespan of Rahukaal varies each day and needs to be calculated as per the sunrise and sunset time.

Rahukaal Calculation
Week Day	Example 1: Sunrise 6:00 a.m. Sunset 6:00 p.m. Time Octant = 90 minutes	Example 2: Sunrise 5:58 a.m. Sunset 8:14 p.m. Time Octant = 107 minutes	Example 3: Sunrise 6:36 a.m. Sunset 6:10 p.m. Time Octant = 87 minutes
Sunday	4:30 p.m. to 6:00 p.m.	6:27 p.m. to 8:14 p.m.	4:43 p.m. to 6:10 p.m.
Monday	7:30 a.m. to 9:00 a.m.	7:45 a.m. to 9:32 a.m.	8:02 a.m. to 9:30 a.m.
Tuesday	3:00 p.m. to 4:30 p.m.	4:40 to 6:27 p.m.	3:16 p.m. to 4:44 p.m.
Wednesday	12 noon to 1:30 p.m.	1:06 p.m. to 2:53 p.m.	12:23 p.m. to 1:50 p.m.
Thursday	1:30 p.m. to 3:00 p.m.	2:53 p.m. to 4:40 p.m.	1:49 p.m. to 3:17 p.m.
Friday	10:30 a.m. to 12 noon	11:19 a.m. to 1:06 p.m.	10:56 p.m. to 12:23 p.m.
Saturday	9:00 a.m. to 10:30 a.m.	9:32 a.m. to 11:19 a.m.	9:29 a.m. to 10:57 a.m.

It’s considered very auspicious to perform Durga Pooja during Rahukaal

Rest any activity or journey, whether of short or long distance, initiated or undertaken during Rahu (Dragon’s Head) Kaal is believed to meet a significant degree of failure, lack of success, delay, postponement or no conclusive results.