According to the Vedic Astrology, certain parts of the day are called Rahu Kalam. During these periods of Rahu Kalam, one should not do any auspicious work, as these periods are not favourable to anyone. The application alerts you about those hours of the day during which you should not engage in any important work.

If the screen color is red, then it shows that it is dragon hour ie. one should not perform any important work during that time and if the screen is green it means it is safe and hence one can do the auspicious work.

Rahu is also called as Dragon’s Head, and the application Dragon Hours , helps you to find evil hours of the day.

The planets according to Indian astronomers are : Sun, Moon, Mars, Mercury, Venus, Jupiter, Saturn, Rahu and Ketu. Rahu Kalam is calculated based on these planets.

Even though Rahu is not physical body, it is a sensitive point on the intersection of the ecliptic (the apparent path of motion of the Sun) by the Moon’s orbit. The ancient zodiac signs have given equal importance to Rahu. However, they did not give any specific day for it as they treated Rahu as nodes. However, Rahu will be given one and half hours time in a day.Out of 24 hours time, if we deduct this one and half hour, it comes to 22.5 hours, which is shared by the seven planets. However, Rahu and Ketu have been given equal powers by Zodiac signs.

According to Hindu Astrology, there are seven days in a week which is from Sunday to Saturday. Each day is being ruled by a particular planet and has its own ruling divinity. The ruling of the day are as follows:

Sunday is ruled by Ravi
Monday is ruled by Chandra
Tuesday is ruled by Kuja
Wednesday is ruled by Budha
Thursday is ruled by Guru
Friday is ruled by Sukra
Saturday is ruled by Saturn

Rahu Kalam differs from place to place depending on Sun-rise & Sun-set time. The day duration from Sun-rise to Sun-set, at a particular location, is divided into eight equal parts. There is no Rahu Kalam during the first period of any weekday. On Monday it falls on the 2nd period, Saturday 3rd period, Friday 4th period, Wednesday 5th period, Thursday 6th period, Tuesday 7th period & Sunday 8th period.

Since the Rahu Kalam is dependent on the Sun-rise and Sun-set timings of your particular location, you must refer to the application everyday in order to avoid the inauspicious hours of the day.