What is Tam Tai?
Tam Tai, literally "three calamities", is a folk belief about three consecutive years in which a person is advised to be more careful. The cycle repeats every twelve years, so nine ordinary years are followed by three Tam Tai years.
It is consulted when choosing a year to marry, to build, to open a business or to sign something large. Among the three house-building taboos it is the only one read from the zodiac animal rather than from a number.
How it is determined
Tam Tai follows the trine of your birth-year branch. There are four groups, each meeting three fixed years: those born in the years of the Monkey, Rat or Dragon meet Tam Tai in Tiger, Rabbit and Dragon years; Tiger, Horse or Dog in Monkey, Rooster and Dog years; Snake, Rooster or Ox in Pig, Rat and Ox years; and Pig, Rabbit or Goat in Snake, Horse and Goat years.
Because the cycle is fixed, anyone can see their three years well in advance without checking year by year.
The three years differ
Tradition distinguishes the entering, central and exiting years of the cycle. Some hold the middle year to be the heaviest, others the last. Schools do not agree on this point.
How to read it
Tam Tai does not mean three years of unbroken misfortune. By its own traditional reading it advises greater caution rather than halting everything: important undertakings can still proceed when well prepared, avoiding haste and overconfidence.
This is folk knowledge without scientific basis. Everyone born within the same trine shares the same three years, meaning a quarter of the population at once, so it is not a private forecast.
In practice, finding a year clear of Kim Lâu, Hoang Ốc and Tam Tai together is difficult, especially during one's own Tam Tai years. Many families proceed when only one applies, often borrowing an age for the rituals.