Tai Sui, also known as Grand Duke Jupiter or Grand Commander of the Year is probably one of the most highly respected and feared deity in the Chinese beliefs. It is said that if your Zodiac animal clashes with the Tai Sui or you have inadvertently offended him, bad luck will befall you for the whole year. In order to have a good and peaceful year, you need to pay your respect to the Tai Sui.
There are two diverging explanation on the origin of Tai Sui. According to the scientific school of thought the Tai Sui phenomena is attributable to the movement of Jupiter (hence the name Grand Duke Jupiter), which impacts the magnetic field around us, depending on the year we were born. The energy field of Jupiter is similar to the rays of the Sun, it can be helpful and it can be harmful to human being. This explanation usually bodes well with the western audience already educated with zodiac systems based on stars and planets.
Whereas in the Chinese mythology, the Tai Sui （太岁) is actually a position in the celestial heavens which is in charge of the world's affairs for a particular year, i.e. determining the annual fortunes of all of us mortal beings. Just as the Jade Emperor is the Ruler of Heaven, the year Tai Sui is the Ruler of Earth. The Taoist calendar is organized unto series of twelve Earthly Branches rotating in accordance to the five elements, resulting in a 60 year cycle. In other words, there are 60 heavenly generals who would rotate to take up this almighty position. A person's happiness, health, luck and fortune are all under his watchful eye. It actually serves as a reminder to stay away from evil activities, to take good care of health and to perform more caring activities. The year Tai Sui will take note of all the good deeds and misdeeds of everyone.
Besides giving the necessary blessing and acting as a guardian to the mortals, each different Tai Sui is used to mark the Lunar Year. In 2015, General Yang Xian assumes duty to replace General Zhang Ci who was reigned supreme in 2014. General Yang Xian (杨仙), the Yi Wei year Tai Sui was born in China during the Song Dynasty. He was a much respected general who shunned fame and material comforts. Leading a hermit lifestyle, Yan Xian loved to go to the mountains and assimilate with nature and wild animals. He had a sharp sense of precognition and was known to be concise and precise.
Yet others have combined both schools of thoughts into one. It is believed the term "Tai Sui" is derived from the "Tai Sui Calendar System" of ancient China. "Sui" originally referred to Jupiter (木星), which was considered the leader of all stars. But it was quite inconvenient to calculate the Heavenly Stems and Earthly Branches based on the movement of Jupiter, so people created an imaginary star moving directly opposite to Jupiter and named it "Tai Sui". As time passes, the Tai Sui Star was personified and transformed from an imaginary star to a deity who has absolute command over worldly affairs.
Therefore irrespective of whether Tai Sui is a deity or a star, it pays to heed the location of the Tai Sui of the year so as not to inadvertently disturb him or it. An offended Tai Sui will cause misfortunes, from mild to the severe kind. Every year, two of the Zodiac animals must take steps to appease the Tai Sui because one is directly afflicted (sitting) while the other is directly in conflict (facing) with the Grand Duke. As Tai Sui is always located in the same compass direction as the Year Animal Sign, this is the afflicted Zodiac while the sign in the diagonally opposite sector is said to be in conflict with Tai Sui. In 2015 Sheep year, the position of Tai Sui is at South West 1 (home sector of the Sheep), so those born in the year of the Sheep are directly afflicted with Tai Sui while the Ox, which is located in NE1, is in direct conflict with Tai Sui. Additionally, the Dragon (SE1) and Dog (NW1) are indirectly in conflict with Tai Sui.
Tai Sui is disturbed when you carry out major works such as construction works or cutting down trees where he is residing for the year. You can offend the Tai Sui in numerous ways, the main ones being “facing” him and also for being born on a certain date. Facing his direction for a prolonged period like working or sleeping will incur his wrath and based on your Chinese Zodiac animal, you may be in a position that “offended” Tai Sui, or in Chinese “Fan Tai Sui”.
If you have incurred the wrath of Tai Sui, remedial steps must be taken to appease him and preventive measures carried out to avoid further offending him. Those who Fan Tai Sui generally will have a not-so-smooth year, all matters relating to your career, health, relationships, etc will be affected.The basic guidelines to heed are: