More precisely, the most solemn day of the Jewish year also is when families with young men of marriageable age look over the families with young women of marriageable age, and vice versa.

The custom of combining the Day of Atonement with preliminary matchmaking originated in talmudic times in Jerusalem, in the courtyard and outside the synagogue. In past centuries, those who were unmarried signaled their availability by wearing white shirts and dresses, says Rabbi David Shofet of the Nessah Educational and Cultural Center in Santa Monica.

Shofet is the spiritual leader of the 30,000-strong Iranian Jewish community in Los Angeles and represents the 13th generation in an unbroken line of rabbis. His father, Yedidia Shofet, bore the honorary title of Chief Rabbi of Tehran in the old country.

So important is the introductory ritual that if a family does not find pleasing prospective partners in one synagogue it will move on to others.

Before the services, a mother will alert any daughter that is age 18 or over that she is dameh bakht -- on the verge of her destiny -- and that if the girl waits too long she will turn torsheedeh, or sour.

The role of both the immediate and extended family in the matchmaking process is crucial.

"In the old days, young people of marriageable age didn't talk to each other," Shofet says. "It was the parents and other close relatives who explored the social and economic status of a potential partner's family and conducted the negotiations."

Some of the old family ties are loosening with assimilation, but it is still extremely rare for young Iranian Jews -- who are mostly observant -- to marry outside the community.