In Hindu Astrology or Vedic Astrology, Rahu Kala or Rahu Kalam is considered inauspicious and any good deed is not started during this time. Many people avoid this time to start a travel. 

The Rahukala spans for approximately 90 minutes every day between Sunrise and Sunset. This inauspicious period is strictly avoided for calculating Muhurtams. However, routine tasks which have already been started are regarded to be permissible during this period. Rahu is a shadow planet and king of meteors among the Navagrahas. 

According to the Legend, during Samudra Mandana, an asura named Svarbhanu, disguised as Deva(Chandra to be precise), appears and drinks the nectar of immortality, amrita. He gets caught and Mahavishnu cuts him into two pieces with his Sudarsana Chakra, the discus. But having drank Amrita he did not die but became two pieces, Rahu and Ketu. 

The Rāhukāla is considered in a predefined manner during set times on the different days of the week but can vary as per the time of sunrise as well. Its instances vary from place to place. The timing of sunrise is marked in the panchangam (almanac) and the 12 hours of the day are divided into eight equal parts. 

Rahu Kalam, Yamagandam, and Kuligai are important astrological timings that are believed to have a significant impact on the fortunes of individuals. It is believed that performing certain activities during these times can have a positive or negative impact on an individual’s life.

Traditional belief suggests that Rahu Kaal is inauspicious because Rahu overpowers the mind and weakens an individual’s ability to think. Therefore, it is best to avoid it while planning auspicious events like marriage, housewarming, a child’s naming ceremony, or other sacred beginnings.

 since Rahu hails from a family of demons, the time he rules or overshadows is deemed malefic. Hence, people who follow the Panchang choose not to begin any auspicious work during Rahu Kaal.

 The time between sunrise and sunset is divided into 8 parts, with each half consisting of an hour and a half. The first segment post sunrise is never influenced by Rahu, and therefore, this period is deemed auspicious. However, Rahu Kaal’s timings change depending on when the sun rises and the place.

Although this time is considered inauspicious, this time is suitable for prayers. Normally, a person should not embark journey during Rahu Kaal. Work, Job interviews, Business dealings, and the sale or acquisition of assets are all prohibited during this time. 

Knowing the Sunday Rahu kalam timing is important because it is the day of Lord Surya, and the timing of Sunday Rahukalam can help you to make or break your chances of success.

Yamakandam:

Yamagandam is a time of the day when Kethu rules for one and a half hours. It is determined by dividing the day into eight parts, each around one and a half hours long. Yamagandam is generally believed to be a time when activities when performed which is not good, will bring bad to the doer. It is considered a destructive time and only death ceremonies are performed during this time.

Any activity performed during that time will be a failure and energies relating to the work will become negative. These 90 minutes (one and a half hours) related to Yamagandam are believed to be related to Kethu Graha or Dragon’s tail. One should avoid starting important business, investment, or travel-related activities, during this Yamagandam time. Yamagandam represents a dangerous time that is considered unfavorable to start any auspicious activity. Only inauspicious ceremonies are performed during Yamagandam.

All the planets have one weekday assigned to them, while Rahu and Ketu do not own any day. Instead, they each rule a time window of one and a half hours every day.Yamagandam is not considered auspicious for any important activities.

Rahu Kalam on Sunday:

4.30 to 6.00 pm

Yama Gandam on Sunday:

12.00 to 1.30 noon