In various cultures there is widespread belief that there are certain crucial years in a person's life where one experiences important physical, mental and social changes. In Japanese tradition, these critical years are known as "yakudoshi."

Yakudoshi can be understood in part as an attempt to provide order and structure to our constantly changing lives. Yakudoshi signals an occasion when the different pieces of a person — body, mind and spirit — are in near balance, whereas at other periods in a person's life one part is dominant over the others. Thus yakudoshi marks a critical stage in adulthood where the opportunity for a person to fully realize his or her potential in life is most available.

There is confusion in Hawai'i, however, as to when yakudoshi should be observed. Some maintain yakudoshi occurs when a man turns 41, others claim it is 42. This confusion stems in part from Japan's change to a Western-based calendar system in the 19th century, a period when the first Japanese immigrants began to make their way to Hawai'i.

According to the old Japanese calendar, a baby was considered 1 year old at birth. After adopting the new calendar, however, a baby was not considered a year old until one year after birth.

Why 42? The power of yakudoshi resides in part in the homonymic qualities of the numbers involved. Pronouncing the numbers 4 (shi) and 2 (ni) in Japanese sounds like the Japanese word for death (shini). Forty-two is thus an age of crisis as it signals the end of a particular stage in a man's life.

The Japanese word for crisis is written with two Chinese characters, one meaning "danger" and the other meaning "opportunity." This suggests that in every crisis there exists the potential for danger and opportunity. The notion behind a man's yakudoshi, then, is that at 42 a man is at a critical juncture in life as his combined social, physical and mental powers are near their peak. In short, at 42 a man should be making his mark in society. After this, his opportunities to do so dwindle.

Women have yakudoshi, too, but the critical year is 33, not 42. Like the male yakudoshi, there is a homonymic quality to the number. Pronouncing the numbers 3 (san) and 3 (zan) sounds like the Japanese word for misery (sanzan). In other words, a woman is in full bloom at this age and will not be happy if she is not making the most of her potential during this period.

It is customary to visit a shrine and receive the blessing of the gods during yakudoshi so that the year will be filled with good fortune. It is also common in Hawai'i for family and friends to throw yakudoshi parties to celebrate the birthday person's status, to ensure that the critical year gets off to a good start, and to ask that the year brings more opportunities than dangers.

It is said we are not born all at once, but by bits. Our bodies are born first and our spirit and character later. In the Japanese tradition of yakudoshi is both the opportunity to unite the disparate parts of a person's life, and the danger of letting them fall to pieces.

Jay Sakashita teaches religion at Leeward Community College. He turned 42 last month.