Under the Flying Star School of Feng Shui, time is divided into three periods (Upper, Middle and Lower period), each of 60 years, and these 60 years are further divided into 3 ages of 20 years each, making up what we call the three periods and nine ages (). Each age has a ruling star or trigram which is expressed in numbers.

For example, the period 1984-2003 is called the Age of Seven and the ruling trigram is Dui (), represented by the number 7.

The nine ages correspond with the nine numbers of the original Lo Shu diagram. This diagram forms the basic of this school of feng shui. The numbers 1 to 9 are arranged around the 9-square grid in such a way that any three numbers add up to fifteen in any direction - whether calculated horizontally, vertically or diagonally. The numbers move or "fly" around the grid in a pre set sequence (see the diagrams below). This sets the flight path for the way all other numerals should "fly". Beginners in this Art are urged to memorize this path using their hand.

Each square represents a direction. There are three numbers in each square. The larger number in the middle is derived from the age of the building. It is sometime referred as the Time Star or the Lo Shu number. The other two smaller numbers represent intangible feng shui influence the house will receive from a particular direction. They are derived from the direction of the sitting (back) and facing (front) of building respectively. The number on the left is the Mountain Star (Sitting Star) and the number on the right is the Water Star (Facing Star). In general, mountain stars influence human health and harmony while water stars affect the wealth and prosperity.

One very important principle to note is that when we have an auspicious star, we want to activate it so as to bring in wealth and prosperity. Similarly when we have a bad water star, we try to minimize activities so as to not aggravate the negative energy present.