A shadow planet and the king of meteors in the solar system, as mentioned in Hindu texts, Rahu is believed to be a malefic planet that tries to eclipse the Sun, and the time it is believed to influence is considered inauspicious.

During the churning of the ocean (samudra manthan), Svarbhanu (an asura), disguised as a deva, drank the elixir (amrita). Once Svarbhanu is caught and is dissected  into two pieces by Vishnu ji's discus (sudarshana chakra). These two pieces became Rahu (the upper part) and Ketu (the lower part).

Rahu and Ketu can even block the Sun and Moon, causing solar and lunar eclipses. Like it causes eclipse (grahan) and masks the Sun from this world, even for a few minutes, Rahu may overshadow the mind during Rahu Kalam, causing it to go blank, thus barring mental clarity. From a scientific perspective, the quantum of UV radiation augments the belief surrounding Rahu Kalam.

 Ancient astrologers noted that during Rahu Kaal, the amount and strength of UV rays was the highest and increased exposure to UV rays had negative effects on health.

Rahu, a significant entity in astrology, affects your life in variant manners. The influence of Rahu in your life depends upon its position in your birth chart.

Inclined to working autonomously, if it is one's ascendant Lord, it may tend to bring challenges in life.

During its Antardasha and Mahadasha phases,  Rahu may effect struggles and problems in various walks of life. But a positive Rahu may see you succeed especially in politics, business, social activism, thus bringing prosperity, and social recognition. Rahu’s impact on life is quite based on its position and its association with other factors in the birth chart.

Rahu Kalam is a certain amount of time each day that lasts approximately for one and half hour. One of the eight segments of the day between sunrise and sunset that is calculated by taking the total time between sunrise and sunset at a given place and then dividing this time duration by eight, Rahu Kalam timings and duration are not same for any two locations due to difference in local timings of sunrise and sunset.

Therefore, Rahu Kalam should be looked at for each day. During the day, we calculate the eight parts of Rahu Kalam by dividing the hours between sunrise and sunset equally. Each day of the week has a different Rahu Kaal time, which depends on the local times of sunrise and sunset. To find out the exact Rahu Kalam for your location, it’s a good idea to consult a local panchang  (astrological calendar).

 Rahu Kalam times for each day of the week:

• On Monday, Rahu Kalam is from 7:30 a.m. to 9:00 a.m., which falls in the second part of the day.
• On Tuesday, Rahu Kalam is from 3:00 p.m. to 4:30 p.m., during the seventh part of the day.
• For Wednesday, Rahu Kalam occurs from 12:00 p.m. to 1:30 p.m., in the fifth part of the day.
• Thursday’s Rahu Kalam is from 1:30 p.m. to 3:00 p.m., in the sixth part of the day.
• Friday’s Rahu Kalam takes place from 10:30 a.m. to 12:00 p.m., during the fourth part of the day.
• On Saturday, it’s from 9:00 a.m. to 10:30 a.m., in the third part of the day.
• And Sunday’s Rahu Kalam occurs from 4:30 p.m. to 6:00 p.m., during the eighth part of the day.